{"id":27487,"date":"2025-04-24T13:56:17","date_gmt":"2025-04-24T06:56:17","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=27487"},"modified":"2025-04-24T14:00:17","modified_gmt":"2025-04-24T07:00:17","slug":"tham-so-parameter-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/","title":{"rendered":"Tham s\u1ed1 (Parameter) l\u00e0 g\u00ec? Gi\u1ea3i th\u00edch \u0111\u1ea7y \u0111\u1ee7 &#038; V\u00ed d\u1ee5 [2025]"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_84 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Tham-so-Parameter-la-gi\" >Tham s\u1ed1 (Parameter) l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Tai-sao-can-su-dung-Tham-so-trong-lap-trinh\" >T\u1ea1i sao c\u1ea7n s\u1eed d\u1ee5ng Tham s\u1ed1 trong l\u1eadp tr\u00ecnh?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Phan-biet-ro-rang-Tham-so-Parameter-vs-Doi-so-Argument\" >Ph\u00e2n bi\u1ec7t r\u00f5 r\u00e0ng: Tham s\u1ed1 (Parameter) vs \u0110\u1ed1i s\u1ed1 (Argument)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Cach-khai-bao-va-su-dung-Tham-so-trong-thuc-te-Vi-du-Code\" >C\u00e1ch khai b\u00e1o v\u00e0 s\u1eed d\u1ee5ng Tham s\u1ed1 trong th\u1ef1c t\u1ebf (V\u00ed d\u1ee5 Code)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Vi-du-voi-Tham-so-vi-tri-Positional-Parameters\" >V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 v\u1ecb tr\u00ed (Positional Parameters)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Vi-du-voi-Tham-so-mac-dinh-Default-Parameters\" >V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh (Default Parameters)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Vi-du-voi-Tham-so-tu-khoa-Keyword-Parameters\" >V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 t\u1eeb kh\u00f3a (Keyword Parameters)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Cac-loai-Tham-so-thuong-gap-trong-lap-trinh\" >C\u00e1c lo\u1ea1i Tham s\u1ed1 th\u01b0\u1eddng g\u1eb7p trong l\u1eadp tr\u00ecnh<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Moi-lien-he-giua-Tham-so-va-Pham-vi-bien-Variable-Scope\" >M\u1ed1i li\u00ean h\u1ec7 gi\u1eefa Tham s\u1ed1 v\u00e0 Ph\u1ea1m vi bi\u1ebfn (Variable Scope)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Luu-y-quan-trong-khi-lam-viec-voi-Tham-so\" >L\u01b0u \u00fd quan tr\u1ecdng khi l\u00e0m vi\u1ec7c v\u1edbi Tham s\u1ed1<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/#Cau-hoi-thuong-gap-ve-Tham-so-FAQ\" >C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 Tham s\u1ed1 (FAQ)<\/a><\/li><\/ul><\/nav><\/div>\n\n<p>Tham s\u1ed1 (parameter) l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m n\u1ec1n t\u1ea3ng, kh\u00f4ng th\u1ec3 thi\u1ebfu \u0111\u1ec3 vi\u1ebft code linh ho\u1ea1t v\u00e0 hi\u1ec7u qu\u1ea3 trong m\u1ecdi ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd d\u1eabn d\u1eaft b\u1ea1n t\u00ecm hi\u1ec3u t\u1eeb A-Z v\u1ec1 ch\u1ee7 \u0111\u1ec1 n\u00e0y: t\u1eeb \u0111\u1ecbnh ngh\u0129a c\u1ed1t l\u00f5i, l\u00fd do c\u1ea7n thi\u1ebft, s\u1ef1 kh\u00e1c bi\u1ec7t m\u1ea5u ch\u1ed1t v\u1edbi \u0111\u1ed1i s\u1ed1 (argument), c\u00e1ch \u1ee9ng d\u1ee5ng th\u1ef1c t\u1ebf qua v\u00ed d\u1ee5 code \u0111a d\u1ea1ng, \u0111\u1ebfn c\u00e1c lo\u1ea1i ph\u1ed5 bi\u1ebfn, ph\u1ea1m vi bi\u1ebfn v\u00e0 c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tham-so-Parameter-la-gi\"><\/span>Tham s\u1ed1 (Parameter) l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong><a href=\"https:\/\/interdata.vn\/blog\/tham-so-parameter-la-gi\/\">Tham s\u1ed1 (parameter)<\/a> trong l\u1eadp tr\u00ecnh l\u00e0 m\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/bien-la-gi\/\">bi\u1ebfn<\/a> \u0111\u1eb7c bi\u1ec7t, \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong ph\u1ea7n khai b\u00e1o c\u1ee7a m\u1ed9t h\u00e0m (function) ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c (method).<\/strong> N\u00f3 ho\u1ea1t \u0111\u1ed9ng nh\u01b0 m\u1ed9t t\u00ean gi\u1eef ch\u1ed7 (placeholder) hay m\u1ed9t &#8220;c\u1ed5ng nh\u1eadn d\u1eef li\u1ec7u&#8221; cho c\u00e1c gi\u00e1 tr\u1ecb s\u1ebd \u0111\u01b0\u1ee3c cung c\u1ea5p t\u1eeb b\u00ean ngo\u00e0i khi h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c \u0111\u00f3 \u0111\u01b0\u1ee3c g\u1ecdi th\u1ef1c thi sau n\u00e0y.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter.jpg\" alt=\"Tham s\u1ed1 (Parameter)\" width=\"750\" height=\"500\" class=\"aligncenter size-full wp-image-27493\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-300x200.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<p>B\u1ea1n c\u00f3 th\u1ec3 xem tham s\u1ed1 nh\u01b0 m\u1ed9t th\u00e0nh ph\u1ea7n trong &#8220;b\u1ea3n thi\u1ebft k\u1ebf&#8221; c\u1ee7a h\u00e0m. N\u00f3 quy \u0111\u1ecbnh lo\u1ea1i th\u00f4ng tin m\u00e0 h\u00e0m c\u1ea7n nh\u1eadn \u0111\u1ec3 c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng. T\u00ean c\u1ee7a tham s\u1ed1 gi\u00fap ch\u00fang ta hi\u1ec3u r\u00f5 h\u01a1n v\u1ec1 m\u1ee5c \u0111\u00edch c\u1ee7a d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o \u0111\u00f3 trong logic x\u1eed l\u00fd c\u1ee7a h\u00e0m.<\/p>\n<p>M\u1ee5c \u0111\u00edch ch\u00ednh c\u1ee7a vi\u1ec7c s\u1eed d\u1ee5ng tham s\u1ed1 l\u00e0 \u0111\u1ec3 t\u0103ng t\u00ednh linh ho\u1ea1t v\u00e0 kh\u1ea3 n\u0103ng t\u00e1i s\u1eed d\u1ee5ng <a href=\"https:\/\/interdata.vn\/blog\/source-code-la-gi\/\">m\u00e3 ngu\u1ed3n<\/a>. Thay v\u00ec ph\u1ea3i vi\u1ebft l\u1ea1i m\u1ed9t h\u00e0m nhi\u1ec1u l\u1ea7n cho c\u00e1c d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o kh\u00e1c nhau, b\u1ea1n c\u00f3 th\u1ec3 d\u00f9ng c\u00f9ng m\u1ed9t h\u00e0m v\u00e0 truy\u1ec1n c\u00e1c gi\u00e1 tr\u1ecb kh\u00e1c nhau th\u00f4ng qua tham s\u1ed1 c\u1ee7a n\u00f3, gi\u00fap code ng\u1eafn g\u1ecdn v\u00e0 d\u1ec5 b\u1ea3o tr\u00ec h\u01a1n.<\/p>\n<p>H\u00e3y h\u00ecnh dung h\u00e0m nh\u01b0 m\u1ed9t c\u00f4ng th\u1ee9c l\u00e0m b\u00e1nh m\u00e0 b\u1ea1n t\u00ecm th\u1ea5y trong s\u00e1ch d\u1ea1y n\u1ea5u \u0103n. <strong>Tham s\u1ed1<\/strong> gi\u1ed1ng nh\u01b0 danh s\u00e1ch c\u00e1c nguy\u00ean li\u1ec7u (v\u00ed d\u1ee5: <code>luong_bot<\/code>, <code>so_luong_trung<\/code>, <code>luong_duong<\/code>) \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea trong ph\u1ea7n chu\u1ea9n b\u1ecb c\u1ee7a c\u00f4ng th\u1ee9c \u0111\u00f3. Ch\u00fang cho b\u1ea1n bi\u1ebft c\u1ea7n chu\u1ea9n b\u1ecb nh\u1eefng g\u00ec.<\/p>\n<p>Khi b\u1ea1n th\u1ef1c s\u1ef1 b\u1eaft tay v\u00e0o l\u00e0m b\u00e1nh (t\u1ee9c l\u00e0 <i>g\u1ecdi h\u00e0m<\/i>), b\u1ea1n s\u1ebd cung c\u1ea5p c\u00e1c nguy\u00ean li\u1ec7u th\u1ef1c t\u1ebf (v\u00ed d\u1ee5: 500g b\u1ed9t, 3 qu\u1ea3 tr\u1ee9ng, 100g \u0111\u01b0\u1eddng). Nh\u1eefng gi\u00e1 tr\u1ecb c\u1ee5 th\u1ec3 n\u00e0y ch\u00ednh l\u00e0 <strong>\u0111\u1ed1i s\u1ed1 (argument)<\/strong>, s\u1ebd \u0111\u01b0\u1ee3c &#8220;\u0111\u1ed5&#8221; v\u00e0o c\u00e1c &#8220;khu\u00f4n&#8221; t\u01b0\u01a1ng \u1ee9ng l\u00e0 tham s\u1ed1 \u0111\u00e3 \u0111\u1ecbnh ngh\u0129a trong c\u00f4ng th\u1ee9c.<\/p>\n<p>Trong m\u00e3 ngu\u1ed3n (source code), b\u1ea1n s\u1ebd th\u1ea5y c\u00e1c tham s\u1ed1 \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong c\u1eb7p d\u1ea5u ngo\u1eb7c \u0111\u01a1n <code>()<\/code> ngay sau t\u00ean c\u1ee7a h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c. V\u00ed d\u1ee5, trong <code>def greet(user_name):<\/code>, th\u00ec <code>user_name<\/code> ch\u00ednh l\u00e0 tham s\u1ed1 c\u1ee7a h\u00e0m <code>greet<\/code>. M\u1ed7i tham s\u1ed1 th\u01b0\u1eddng c\u00f3 m\u1ed9t t\u00ean v\u00e0 \u0111\u00f4i khi \u0111i k\u00e8m ki\u1ec3u d\u1eef li\u1ec7u n\u00f3 d\u1ef1 ki\u1ebfn nh\u1eadn.<\/p>\n<p>V\u1ec1 b\u1ea3n ch\u1ea5t, tham s\u1ed1 ho\u1ea1t \u0111\u1ed9ng nh\u01b0 nh\u1eefng <strong>bi\u1ebfn c\u1ee5c b\u1ed9 (local variable)<\/strong> b\u00ean trong h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c. Ch\u00fang ch\u1ec9 t\u1ed3n t\u1ea1i v\u00e0 c\u00f3 th\u1ec3 truy c\u1eadp \u0111\u01b0\u1ee3c trong ph\u1ea1m vi (scope) c\u1ee7a h\u00e0m\/ph\u01b0\u01a1ng th\u1ee9c \u0111\u00f3. Ch\u00fang nh\u1eadn gi\u00e1 tr\u1ecb t\u1eeb b\u00ean ngo\u00e0i th\u00f4ng qua c\u00e1c \u0111\u1ed1i s\u1ed1 \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o khi h\u00e0m \u0111\u01b0\u1ee3c g\u1ecdi, l\u00e0m c\u1ea7u n\u1ed1i gi\u1eefa th\u1ebf gi\u1edbi b\u00ean ngo\u00e0i v\u00e0 logic x\u1eed l\u00fd b\u00ean trong h\u00e0m.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tai-sao-can-su-dung-Tham-so-trong-lap-trinh\"><\/span>T\u1ea1i sao c\u1ea7n s\u1eed d\u1ee5ng Tham s\u1ed1 trong l\u1eadp tr\u00ecnh?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>B\u1ea1n c\u00f3 th\u1ec3 th\u1eafc m\u1eafc, t\u1ea1i sao kh\u00f4ng vi\u1ebft th\u1eb3ng gi\u00e1 tr\u1ecb v\u00e0o trong h\u00e0m m\u00e0 c\u1ea7n \u0111\u1ebfn tham s\u1ed1 l\u00e0m g\u00ec? Tham s\u1ed1 mang l\u1ea1i nh\u1eefng l\u1ee3i \u00edch v\u00f4 c\u00f9ng to l\u1edbn, l\u00e0 n\u1ec1n t\u1ea3ng cho vi\u1ec7c vi\u1ebft code hi\u1ec7u qu\u1ea3 v\u00e0 chuy\u00ean nghi\u1ec7p.<\/p>\n<p>L\u1ee3i \u00edch r\u00f5 r\u00e0ng nh\u1ea5t l\u00e0 <strong>t\u0103ng t\u00ednh linh ho\u1ea1t<\/strong>. M\u1ed9t h\u00e0m \u0111\u01b0\u1ee3c vi\u1ebft v\u1edbi tham s\u1ed1 c\u00f3 th\u1ec3 x\u1eed l\u00fd nhi\u1ec1u lo\u1ea1i d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o kh\u00e1c nhau. V\u00ed d\u1ee5, thay v\u00ec vi\u1ebft h\u00e0m <code>tinh_tong_2_va_3()<\/code> v\u00e0 <code>tinh_tong_5_va_7()<\/code>, b\u1ea1n ch\u1ec9 c\u1ea7n vi\u1ebft m\u1ed9t h\u00e0m <code>tinh_tong(so_a, so_b)<\/code> nh\u1eadn hai tham s\u1ed1.<\/p>\n<p>Khi c\u1ea7n t\u00ednh t\u1ed5ng c\u1ee7a hai s\u1ed1 b\u1ea5t k\u1ef3, b\u1ea1n ch\u1ec9 vi\u1ec7c g\u1ecdi h\u00e0m <code>tinh_tong<\/code> v\u00e0 truy\u1ec1n gi\u00e1 tr\u1ecb c\u1ee5 th\u1ec3 (\u0111\u1ed1i s\u1ed1) v\u00e0o, v\u00ed d\u1ee5 <code>tinh_tong(2, 3)<\/code> ho\u1eb7c <code>tinh_tong(5, 7)<\/code>. H\u00e0m c\u1ee7a b\u1ea1n tr\u1edf n\u00ean \u0111a d\u1ee5ng h\u01a1n r\u1ea5t nhi\u1ec1u.<\/p>\n<p>\u0110i\u1ec1u n\u00e0y d\u1eabn tr\u1ef1c ti\u1ebfp \u0111\u1ebfn l\u1ee3i \u00edch th\u1ee9 hai: <strong>t\u0103ng kh\u1ea3 n\u0103ng t\u00e1i s\u1eed d\u1ee5ng code (code reusability)<\/strong>. B\u1ea1n ch\u1ec9 c\u1ea7n vi\u1ebft logic t\u00ednh t\u1ed5ng m\u1ed9t l\u1ea7n duy nh\u1ea5t trong h\u00e0m <code>tinh_tong<\/code>. B\u1ea5t c\u1ee9 khi n\u00e0o c\u1ea7n th\u1ef1c hi\u1ec7n ph\u00e9p c\u1ed9ng, b\u1ea1n g\u1ecdi l\u1ea1i h\u00e0m n\u00e0y thay v\u00ec sao ch\u00e9p v\u00e0 d\u00e1n (copy-paste) \u0111o\u1ea1n m\u00e3 t\u00ednh t\u1ed5ng nhi\u1ec1u l\u1ea7n.<\/p>\n<p>Vi\u1ec7c t\u00e1i s\u1eed d\u1ee5ng code gi\u00fap ch\u01b0\u01a1ng tr\u00ecnh ng\u1eafn g\u1ecdn h\u01a1n, gi\u1ea3m thi\u1ec3u l\u1ed7i (v\u00ec ch\u1ec9 s\u1eeda logic \u1edf m\u1ed9t n\u01a1i n\u1ebfu c\u1ea7n) v\u00e0 ti\u1ebft ki\u1ec7m th\u1eddi gian ph\u00e1t tri\u1ec3n \u0111\u00e1ng k\u1ec3. \u0110\u00e2y l\u00e0 m\u1ed9t nguy\u00ean t\u1eafc c\u1ef1c k\u1ef3 quan tr\u1ecdng trong k\u1ef9 thu\u1eadt ph\u1ea7n m\u1ec1m.<\/p>\n<p>H\u00e3y t\u01b0\u1edfng t\u01b0\u1ee3ng b\u1ea1n c\u1ea7n t\u00ednh di\u1ec7n t\u00edch h\u00ecnh ch\u1eef nh\u1eadt. N\u1ebfu kh\u00f4ng d\u00f9ng tham s\u1ed1, b\u1ea1n c\u00f3 th\u1ec3 ph\u1ea3i vi\u1ebft c\u00e1c h\u00e0m nh\u01b0:<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># C\u00e1ch l\u00e0m t\u1ec7: Kh\u00f4ng d\u00f9ng tham s\u1ed1\r\ndef tinh_dien_tich_5x10():\r\n  return 5 * 10\r\n\r\ndef tinh_dien_tich_7x3():\r\n  return 7 * 3\r\n\r\n# ... v\u00e0 r\u1ea5t nhi\u1ec1u h\u00e0m kh\u00e1c cho m\u1ed7i k\u00edch th\u01b0\u1edbc\r\n<\/code><\/pre>\n<p>C\u00e1ch l\u00e0m n\u00e0y r\u1ea5t t\u1ec7 v\u00ec l\u1eb7p \u0111i l\u1eb7p l\u1ea1i logic <code>d\u00e0i * r\u1ed9ng<\/code>.<\/p>\n<p>Thay v\u00e0o \u0111\u00f3, v\u1edbi tham s\u1ed1, b\u1ea1n ch\u1ec9 c\u1ea7n:<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># C\u00e1ch l\u00e0m t\u1ed1t: D\u00f9ng tham s\u1ed1\r\ndef tinh_dien_tich(chieu_dai, chieu_rong): # chieu_dai, chieu_rong l\u00e0 tham s\u1ed1\r\n  return chieu_dai * chieu_rong\r\n\r\n# G\u1ecdi h\u00e0m v\u1edbi c\u00e1c \u0111\u1ed1i s\u1ed1 kh\u00e1c nhau\r\ndt1 = tinh_dien_tich(5, 10) # 5, 10 l\u00e0 \u0111\u1ed1i s\u1ed1\r\ndt2 = tinh_dien_tich(7, 3)  # 7, 3 l\u00e0 \u0111\u1ed1i s\u1ed1\r\nprint(dt1) # Output: 50\r\nprint(dt2) # Output: 21\r\n<\/code><\/pre>\n<p>R\u00f5 r\u00e0ng c\u00e1ch d\u00f9ng tham s\u1ed1 hi\u1ec7u qu\u1ea3 h\u01a1n h\u1eb3n!<\/p>\n<p>Cu\u1ed1i c\u00f9ng, tham s\u1ed1 h\u1ed7 tr\u1ee3 <strong>module h\u00f3a ch\u01b0\u01a1ng tr\u00ecnh (modularity)<\/strong>. Ch\u00fang gi\u00fap \u0111\u00f3ng g\u00f3i m\u1ed9t ph\u1ea7n logic c\u1ee5 th\u1ec3 v\u00e0o trong m\u1ed9t h\u00e0m, v\u00e0 h\u00e0m n\u00e0y giao ti\u1ebfp v\u1edbi ph\u1ea7n c\u00f2n l\u1ea1i c\u1ee7a ch\u01b0\u01a1ng tr\u00ecnh th\u00f4ng qua c\u00e1c tham s\u1ed1 (\u0111\u1ea7u v\u00e0o) v\u00e0 gi\u00e1 tr\u1ecb tr\u1ea3 v\u1ec1 (\u0111\u1ea7u ra). \u0110i\u1ec1u n\u00e0y l\u00e0m cho c\u1ea5u tr\u00fac ch\u01b0\u01a1ng tr\u00ecnh r\u00f5 r\u00e0ng, d\u1ec5 qu\u1ea3n l\u00fd v\u00e0 d\u1ec5 g\u1ee1 l\u1ed7i h\u01a1n.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01.jpg\" alt=\"Tham s\u1ed1 (Parameter) 01\" width=\"750\" height=\"750\" class=\"aligncenter size-full wp-image-27491\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01-300x300.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01-150x150.jpg 150w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01-75x75.jpg 75w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-01-350x350.jpg 350w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Phan-biet-ro-rang-Tham-so-Parameter-vs-Doi-so-Argument\"><\/span>Ph\u00e2n bi\u1ec7t r\u00f5 r\u00e0ng: Tham s\u1ed1 (Parameter) vs \u0110\u1ed1i s\u1ed1 (Argument)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u00e2y l\u00e0 \u0111i\u1ec3m g\u00e2y nh\u1ea7m l\u1eabn ph\u1ed5 bi\u1ebfn nh\u1ea5t cho ng\u01b0\u1eddi m\u1edbi h\u1ecdc l\u1eadp tr\u00ecnh. D\u00f9 th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng thay th\u1ebf nhau trong giao ti\u1ebfp th\u00f4ng th\u01b0\u1eddng, <strong>tham s\u1ed1 (parameter)<\/strong> v\u00e0 <strong>\u0111\u1ed1i s\u1ed1 (argument)<\/strong> c\u00f3 \u00fd ngh\u0129a k\u1ef9 thu\u1eadt kh\u00e1c bi\u1ec7t r\u00f5 r\u00e0ng. Vi\u1ec7c hi\u1ec3u r\u00f5 s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y l\u00e0 r\u1ea5t quan tr\u1ecdng.<\/p>\n<p><strong>Tham s\u1ed1 (Parameter):<\/strong><\/p>\n<ul>\n<li>L\u00e0 <strong>bi\u1ebfn<\/strong> \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea b\u00ean trong d\u1ea5u ngo\u1eb7c \u0111\u01a1n <code>()<\/code> trong ph\u1ea7n <strong>khai b\u00e1o (definition)<\/strong> c\u1ee7a h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c.<\/li>\n<li>N\u00f3 gi\u1ed1ng nh\u01b0 m\u1ed9t <strong>ch\u1ed7 gi\u1eef ch\u1ed7 (placeholder)<\/strong> ho\u1eb7c m\u1ed9t c\u00e1i t\u00ean \u0111\u1ea1i di\u1ec7n cho gi\u00e1 tr\u1ecb s\u1ebd \u0111\u01b0\u1ee3c nh\u1eadn v\u00e0o.<\/li>\n<li>N\u00f3 thu\u1ed9c v\u1ec1 &#8220;thi\u1ebft k\u1ebf&#8221; c\u1ee7a h\u00e0m, quy \u0111\u1ecbnh lo\u1ea1i d\u1eef li\u1ec7u h\u00e0m c\u1ea7n.<\/li>\n<li>V\u00ed d\u1ee5: Trong <code>def tinh_tong(so_hang_1, so_hang_2):<\/code>, th\u00ec <code>so_hang_1<\/code> v\u00e0 <code>so_hang_2<\/code> l\u00e0 c\u00e1c <strong>tham s\u1ed1<\/strong>.<\/li>\n<\/ul>\n<p><strong>\u0110\u1ed1i s\u1ed1 (Argument):<\/strong><\/p>\n<ul>\n<li>L\u00e0 <strong>gi\u00e1 tr\u1ecb th\u1ef1c t\u1ebf<\/strong> \u0111\u01b0\u1ee3c <strong>truy\u1ec1n v\u00e0o<\/strong> cho c\u00e1c tham s\u1ed1 t\u01b0\u01a1ng \u1ee9ng khi h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c \u0111\u01b0\u1ee3c <strong>g\u1ecdi (called\/invoked)<\/strong>.<\/li>\n<li>N\u00f3 l\u00e0 d\u1eef li\u1ec7u c\u1ee5 th\u1ec3 m\u00e0 h\u00e0m s\u1ebd s\u1eed d\u1ee5ng \u0111\u1ec3 th\u1ef1c hi\u1ec7n c\u00f4ng vi\u1ec7c c\u1ee7a m\u00ecnh.<\/li>\n<li>N\u00f3 thu\u1ed9c v\u1ec1 &#8220;th\u1ef1c thi&#8221; c\u1ee7a h\u00e0m.<\/li>\n<li>V\u00ed d\u1ee5: Khi b\u1ea1n g\u1ecdi <code>ket_qua = tinh_tong(5, 10)<\/code>, th\u00ec <code>5<\/code> v\u00e0 <code>10<\/code> l\u00e0 c\u00e1c <strong>\u0111\u1ed1i s\u1ed1<\/strong>.<\/li>\n<\/ul>\n<p>\u0110\u1ec3 d\u1ec5 h\u00ecnh dung h\u01a1n, h\u00e3y xem x\u00e9t v\u00ed d\u1ee5 h\u00e0m <code>xin_chao<\/code> trong Python:<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># Khai b\u00e1o h\u00e0m v\u1edbi m\u1ed9t tham s\u1ed1 t\u00ean l\u00e0 'ten_nguoi_dung'\r\ndef xin_chao(ten_nguoi_dung): # ten_nguoi_dung l\u00e0 PARAMETER\r\n  \"\"\"H\u00e0m n\u00e0y in l\u1eddi ch\u00e0o \u0111\u1ebfn ng\u01b0\u1eddi d\u00f9ng.\"\"\"\r\n  print(f\"Xin ch\u00e0o, {ten_nguoi_dung}! Ch\u00fac b\u1ea1n m\u1ed9t ng\u00e0y t\u1ed1t l\u00e0nh.\")\r\n\r\n# G\u1ecdi h\u00e0m l\u1ea7n 1\r\nxin_chao(\"An\") # \"An\" l\u00e0 ARGUMENT \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o cho parameter ten_nguoi_dung\r\n\r\n# G\u1ecdi h\u00e0m l\u1ea7n 2\r\nten_cua_ban = \"B\u00ecnh\"\r\nxin_chao(ten_cua_ban) # Bi\u1ebfn ten_cua_ban ch\u1ee9a gi\u00e1 tr\u1ecb \"B\u00ecnh\"\r\n                     # Gi\u00e1 tr\u1ecb \"B\u00ecnh\" l\u00e0 ARGUMENT \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o\r\n<\/code><\/pre>\n<p>Trong v\u00ed d\u1ee5 tr\u00ean:<\/p>\n<ul>\n<li><code>ten_nguoi_dung<\/code> trong d\u00f2ng <code>def xin_chao(ten_nguoi_dung):<\/code> l\u00e0 <strong>tham s\u1ed1<\/strong>. N\u00f3 l\u00e0 t\u00ean bi\u1ebfn \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong h\u00e0m.<\/li>\n<li>Chu\u1ed7i <code>\"An\"<\/code> trong d\u00f2ng <code>xin_chao(\"An\")<\/code> l\u00e0 <strong>\u0111\u1ed1i s\u1ed1<\/strong>. \u0110\u00e2y l\u00e0 gi\u00e1 tr\u1ecb c\u1ee5 th\u1ec3 \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o khi g\u1ecdi h\u00e0m.<\/li>\n<li>Gi\u00e1 tr\u1ecb <code>\"B\u00ecnh\"<\/code> (l\u1ea5y t\u1eeb bi\u1ebfn <code>ten_cua_ban<\/code>) trong d\u00f2ng <code>xin_chao(ten_cua_ban)<\/code> c\u0169ng l\u00e0 <strong>\u0111\u1ed1i s\u1ed1<\/strong>.<\/li>\n<\/ul>\n<p>Khi h\u00e0m <code>xin_chao(\"An\")<\/code> \u0111\u01b0\u1ee3c g\u1ecdi, gi\u00e1 tr\u1ecb <code>\"An\"<\/code> (\u0111\u1ed1i s\u1ed1) s\u1ebd \u0111\u01b0\u1ee3c g\u00e1n cho bi\u1ebfn <code>ten_nguoi_dung<\/code> (tham s\u1ed1) b\u00ean trong h\u00e0m. Sau \u0111\u00f3, h\u00e0m s\u1ebd th\u1ef1c thi l\u1ec7nh <code>print<\/code> v\u1edbi gi\u00e1 tr\u1ecb n\u00e0y.<\/p>\n<p>Hi\u1ec3u r\u00f5 s\u1ef1 kh\u00e1c bi\u1ec7t n\u00e0y gi\u00fap b\u1ea1n \u0111\u1ecdc hi\u1ec3u code d\u1ec5 d\u00e0ng h\u01a1n v\u00e0 tr\u00e1nh c\u00e1c l\u1ed7i li\u00ean quan \u0111\u1ebfn vi\u1ec7c truy\u1ec1n sai ho\u1eb7c thi\u1ebfu \u0111\u1ed1i s\u1ed1 khi g\u1ecdi h\u00e0m.<\/p>\n<figure class=\"table\">\n<table>\n<thead>\n<tr>\n<th>\u0110\u1eb7c \u0111i\u1ec3m<\/th>\n<th>Tham s\u1ed1 (Parameter)<\/th>\n<th>\u0110\u1ed1i s\u1ed1 (Argument)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Xu\u1ea5t hi\u1ec7n \u1edf<\/strong><\/td>\n<td>Khai b\u00e1o h\u00e0m\/ph\u01b0\u01a1ng th\u1ee9c (Definition)<\/td>\n<td>L\u1eddi g\u1ecdi h\u00e0m\/ph\u01b0\u01a1ng th\u1ee9c (Call)<\/td>\n<\/tr>\n<tr>\n<td><strong>B\u1ea3n ch\u1ea5t l\u00e0<\/strong><\/td>\n<td>Bi\u1ebfn (Variable)<\/td>\n<td>Gi\u00e1 tr\u1ecb (Value)<\/td>\n<\/tr>\n<tr>\n<td><strong>Vai tr\u00f2<\/strong><\/td>\n<td>T\u00ean gi\u1eef ch\u1ed7, quy \u0111\u1ecbnh \u0111\u1ea7u v\u00e0o<\/td>\n<td>D\u1eef li\u1ec7u th\u1ef1c t\u1ebf \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o<\/td>\n<\/tr>\n<tr>\n<td><strong>V\u00ed d\u1ee5 (Code)<\/strong><\/td>\n<td><code>def func(param):<\/code><\/td>\n<td><code>func(arg)<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Cach-khai-bao-va-su-dung-Tham-so-trong-thuc-te-Vi-du-Code\"><\/span>C\u00e1ch khai b\u00e1o v\u00e0 s\u1eed d\u1ee5ng Tham s\u1ed1 trong th\u1ef1c t\u1ebf (V\u00ed d\u1ee5 Code)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>C\u00fa ph\u00e1p khai b\u00e1o tham s\u1ed1 c\u00f3 th\u1ec3 h\u01a1i kh\u00e1c nhau gi\u1eefa c\u00e1c ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh, nh\u01b0ng nguy\u00ean t\u1eafc chung l\u00e0 li\u1ec7t k\u00ea t\u00ean c\u00e1c tham s\u1ed1 b\u00ean trong c\u1eb7p d\u1ea5u ngo\u1eb7c \u0111\u01a1n <code>()<\/code> sau t\u00ean h\u00e0m\/ph\u01b0\u01a1ng th\u1ee9c. C\u00e1c tham s\u1ed1 th\u01b0\u1eddng \u0111\u01b0\u1ee3c ph\u00e2n t\u00e1ch b\u1eb1ng d\u1ea5u ph\u1ea9y <code>,<\/code>.<\/p>\n<p>V\u00ed d\u1ee5 c\u00fa ph\u00e1p c\u01a1 b\u1ea3n:<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># Python\r\ndef ten_ham(tham_so_1, tham_so_2):\r\n  # Th\u00e2n h\u00e0m x\u1eed l\u00fd logic\r\n  pass # L\u1ec7nh gi\u1eef ch\u1ed7, kh\u00f4ng l\u00e0m g\u00ec c\u1ea3\r\n\r\n# <a href=\"https:\/\/interdata.vn\/blog\/javascript-la-gi\/\">JavaScript<\/a>\r\nfunction tenHam(thamSo1, thamSo2) {\r\n  \/\/ Th\u00e2n h\u00e0m x\u1eed l\u00fd logic\r\n}\r\n\r\n# <a href=\"https:\/\/interdata.vn\/blog\/ngon-ngu-lap-trinh-java\/\">Java<\/a>\r\npublic returnType tenHam(DataType thamSo1, DataType thamSo2) {\r\n  \/\/ Th\u00e2n h\u00e0m x\u1eed l\u00fd logic\r\n}\r\n<\/code><\/pre>\n<p>Trong nhi\u1ec1u ng\u00f4n ng\u1eef (nh\u01b0 Java, C++), b\u1ea1n c\u1ea7n ch\u1ec9 \u0111\u1ecbnh r\u00f5 ki\u1ec3u d\u1eef li\u1ec7u (Data Type) cho t\u1eebng tham s\u1ed1. Trong c\u00e1c ng\u00f4n ng\u1eef nh\u01b0 Python, JavaScript, vi\u1ec7c n\u00e0y th\u01b0\u1eddng kh\u00f4ng b\u1eaft bu\u1ed9c khi khai b\u00e1o, nh\u01b0ng r\u1ea5t h\u1eefu \u00edch cho vi\u1ec7c \u0111\u1ecdc hi\u1ec3u v\u00e0 ki\u1ec3m tra l\u1ed7i sau n\u00e0y.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 c\u00e1ch s\u1eed d\u1ee5ng tham s\u1ed1 ph\u1ed5 bi\u1ebfn qua v\u00ed d\u1ee5 c\u1ee5 th\u1ec3, ch\u1ee7 y\u1ebfu d\u00f9ng Python v\u00e0 JavaScript cho d\u1ec5 hi\u1ec3u v\u1edbi ng\u01b0\u1eddi m\u1edbi.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Vi-du-voi-Tham-so-vi-tri-Positional-Parameters\"><\/span>V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 v\u1ecb tr\u00ed (Positional Parameters)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 lo\u1ea1i tham s\u1ed1 c\u01a1 b\u1ea3n v\u00e0 ph\u1ed5 bi\u1ebfn nh\u1ea5t. Khi b\u1ea1n g\u1ecdi h\u00e0m, c\u00e1c \u0111\u1ed1i s\u1ed1 b\u1ea1n truy\u1ec1n v\u00e0o s\u1ebd \u0111\u01b0\u1ee3c g\u00e1n cho c\u00e1c tham s\u1ed1 t\u01b0\u01a1ng \u1ee9ng d\u1ef1a tr\u00ean <strong>v\u1ecb tr\u00ed<\/strong> c\u1ee7a ch\u00fang. \u0110\u1ed1i s\u1ed1 \u0111\u1ea7u ti\u00ean g\u00e1n cho tham s\u1ed1 \u0111\u1ea7u ti\u00ean, \u0111\u1ed1i s\u1ed1 th\u1ee9 hai cho tham s\u1ed1 th\u1ee9 hai, v\u00e0 c\u1ee9 th\u1ebf ti\u1ebfp t\u1ee5c.<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># Python\r\ndef mo_ta_thu_cung(loai_thu_cung, ten_thu_cung):\r\n  \"\"\"H\u00e0m m\u00f4 t\u1ea3 th\u00f4ng tin th\u00fa c\u01b0ng.\"\"\"\r\n  print(f\"T\u00f4i c\u00f3 m\u1ed9t con {loai_thu_cung}.\")\r\n  print(f\"T\u00ean c\u1ee7a n\u00f3 l\u00e0 {ten_thu_cung}.\")\r\n\r\n# G\u1ecdi h\u00e0m v\u1edbi \u0111\u1ed1i s\u1ed1 v\u1ecb tr\u00ed\r\nmo_ta_thu_cung(\"m\u00e8o\", \"Luna\")\r\n# Output:\r\n# T\u00f4i c\u00f3 m\u1ed9t con m\u00e8o.\r\n# T\u00ean c\u1ee7a n\u00f3 l\u00e0 Luna.\r\n\r\n# N\u1ebfu \u0111\u1ed5i v\u1ecb tr\u00ed \u0111\u1ed1i s\u1ed1, k\u1ebft qu\u1ea3 s\u1ebd sai logic\r\nmo_ta_thu_cung(\"Max\", \"ch\u00f3\")\r\n# Output:\r\n# T\u00f4i c\u00f3 m\u1ed9t con Max. &lt;--- Sai logic\r\n# T\u00ean c\u1ee7a n\u00f3 l\u00e0 ch\u00f3.  &lt;--- Sai logic\r\n<\/code><\/pre>\n<p>Nh\u01b0 b\u1ea1n th\u1ea5y, th\u1ee9 t\u1ef1 truy\u1ec1n \u0111\u1ed1i s\u1ed1 (&#8220;m\u00e8o&#8221;, &#8220;Luna&#8221;) r\u1ea5t quan tr\u1ecdng. N\u00f3 ph\u1ea3i kh\u1edbp v\u1edbi th\u1ee9 t\u1ef1 khai b\u00e1o tham s\u1ed1 (<code>loai_thu_cung<\/code>, <code>ten_thu_cung<\/code>).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Vi-du-voi-Tham-so-mac-dinh-Default-Parameters\"><\/span>V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh (Default Parameters)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00f4i khi, b\u1ea1n mu\u1ed1n m\u1ed9t tham s\u1ed1 c\u00f3 s\u1eb5n m\u1ed9t gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh n\u1ebfu ng\u01b0\u1eddi d\u00f9ng kh\u00f4ng cung c\u1ea5p \u0111\u1ed1i s\u1ed1 t\u01b0\u01a1ng \u1ee9ng khi g\u1ecdi h\u00e0m. \u0110i\u1ec1u n\u00e0y l\u00e0m cho h\u00e0m linh ho\u1ea1t h\u01a1n. B\u1ea1n khai b\u00e1o gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh b\u1eb1ng c\u00e1ch d\u00f9ng d\u1ea5u <code>=<\/code> ngay sau t\u00ean tham s\u1ed1.<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># Python\r\ndef tinh_luy_thua(co_so, so_mu=2): # so_mu c\u00f3 gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh l\u00e0 2\r\n  \"\"\"T\u00ednh l\u0169y th\u1eeba c\u1ee7a c\u01a1 s\u1ed1 v\u1edbi s\u1ed1 m\u0169 cho tr\u01b0\u1edbc.\"\"\"\r\n  ket_qua = co_so ** so_mu\r\n  print(f\"{co_so} l\u0169y th\u1eeba {so_mu} l\u00e0 {ket_qua}\")\r\n\r\n# G\u1ecdi h\u00e0m, kh\u00f4ng cung c\u1ea5p \u0111\u1ed1i s\u1ed1 cho so_mu =&gt; d\u00f9ng gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh 2\r\ntinh_luy_thua(5)\r\n# Output: 5 l\u0169y th\u1eeba 2 l\u00e0 25\r\n\r\n# G\u1ecdi h\u00e0m, cung c\u1ea5p \u0111\u1ed1i s\u1ed1 cho so_mu =&gt; ghi \u0111\u00e8 gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh\r\ntinh_luy_thua(3, 3)\r\n# Output: 3 l\u0169y th\u1eeba 3 l\u00e0 27\r\n<\/code><\/pre>\n<p>JavaScript<\/p>\n<pre><code class=\"language-plaintext\">\/\/ JavaScript (ES6+)\r\nfunction chaoHoi(ten, loiChao = \"Xin ch\u00e0o\") { \/\/ loiChao c\u00f3 gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh\r\n  console.log(`${loiChao}, ${ten}!`);\r\n}\r\n\r\nchaoHoi(\"Lan\"); \/\/ Output: Xin ch\u00e0o, Lan!\r\nchaoHoi(\"T\u00fa\", \"Ch\u00e0o bu\u1ed5i s\u00e1ng\"); \/\/ Output: Ch\u00e0o bu\u1ed5i s\u00e1ng, T\u00fa!\r\n<\/code><\/pre>\n<p>Tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh r\u1ea5t h\u1eefu \u00edch khi b\u1ea1n mu\u1ed1n cung c\u1ea5p c\u00e1c t\u00f9y ch\u1ecdn c\u1ea5u h\u00ecnh ho\u1eb7c c\u00e1c gi\u00e1 tr\u1ecb ph\u1ed5 bi\u1ebfn m\u00e0 ng\u01b0\u1eddi d\u00f9ng kh\u00f4ng nh\u1ea5t thi\u1ebft ph\u1ea3i ch\u1ec9 \u0111\u1ecbnh m\u1ed7i l\u1ea7n g\u1ecdi h\u00e0m. L\u01b0u \u00fd: C\u00e1c tham s\u1ed1 c\u00f3 gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh th\u01b0\u1eddng ph\u1ea3i \u0111\u01b0\u1ee3c \u0111\u1eb7t sau c\u00e1c tham s\u1ed1 kh\u00f4ng c\u00f3 gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh trong danh s\u00e1ch tham s\u1ed1 (quy t\u1eafc n\u00e0y \u00e1p d\u1ee5ng cho Python v\u00e0 nhi\u1ec1u ng\u00f4n ng\u1eef kh\u00e1c).<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Vi-du-voi-Tham-so-tu-khoa-Keyword-Parameters\"><\/span>V\u00ed d\u1ee5 v\u1edbi Tham s\u1ed1 t\u1eeb kh\u00f3a (Keyword Parameters)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong m\u1ed9t s\u1ed1 ng\u00f4n ng\u1eef nh\u01b0 Python, b\u1ea1n c\u00f3 th\u1ec3 truy\u1ec1n \u0111\u1ed1i s\u1ed1 b\u1eb1ng c\u00e1ch ch\u1ec9 \u0111\u1ecbnh r\u00f5 t\u00ean tham s\u1ed1 m\u00e0 b\u1ea1n mu\u1ed1n g\u00e1n gi\u00e1 tr\u1ecb cho n\u00f3, s\u1eed d\u1ee5ng c\u00fa ph\u00e1p <code>ten_tham_so=gia_tri<\/code>. \u01afu \u0111i\u1ec3m l\u1edbn c\u1ee7a c\u00e1ch n\u00e0y l\u00e0 th\u1ee9 t\u1ef1 truy\u1ec1n \u0111\u1ed1i s\u1ed1 kh\u00f4ng c\u00f2n quan tr\u1ecdng n\u1eefa, v\u00e0 code tr\u1edf n\u00ean d\u1ec5 \u0111\u1ecdc h\u01a1n, \u0111\u1eb7c bi\u1ec7t v\u1edbi c\u00e1c h\u00e0m c\u00f3 nhi\u1ec1u tham s\u1ed1.<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\"># Python - S\u1eed d\u1ee5ng l\u1ea1i h\u00e0m mo_ta_thu_cung\r\ndef mo_ta_thu_cung(loai_thu_cung, ten_thu_cung):\r\n  \"\"\"H\u00e0m m\u00f4 t\u1ea3 th\u00f4ng tin th\u00fa c\u01b0ng.\"\"\"\r\n  print(f\"T\u00f4i c\u00f3 m\u1ed9t con {loai_thu_cung}.\")\r\n  print(f\"T\u00ean c\u1ee7a n\u00f3 l\u00e0 {ten_thu_cung}.\")\r\n\r\n# G\u1ecdi h\u00e0m s\u1eed d\u1ee5ng \u0111\u1ed1i s\u1ed1 t\u1eeb kh\u00f3a\r\nmo_ta_thu_cung(ten_thu_cung=\"Goldie\", loai_thu_cung=\"c\u00e1 v\u00e0ng\")\r\n# Output:\r\n# T\u00f4i c\u00f3 m\u1ed9t con c\u00e1 v\u00e0ng.\r\n# T\u00ean c\u1ee7a n\u00f3 l\u00e0 Goldie.\r\n\r\n# Th\u1ee9 t\u1ef1 kh\u00f4ng quan tr\u1ecdng khi d\u00f9ng t\u1eeb kh\u00f3a\r\nmo_ta_thu_cung(loai_thu_cung=\"ch\u00f3\", ten_thu_cung=\"Max\")\r\n# Output:\r\n# T\u00f4i c\u00f3 m\u1ed9t con ch\u00f3.\r\n# T\u00ean c\u1ee7a n\u00f3 l\u00e0 Max.\r\n<\/code><\/pre>\n<p>Khi s\u1eed d\u1ee5ng \u0111\u1ed1i s\u1ed1 t\u1eeb kh\u00f3a, b\u1ea1n ch\u1ec9 c\u1ea7n nh\u1edb t\u00ean tham s\u1ed1 thay v\u00ec v\u1ecb tr\u00ed ch\u00ednh x\u00e1c c\u1ee7a n\u00f3. B\u1ea1n c\u0169ng c\u00f3 th\u1ec3 k\u1ebft h\u1ee3p \u0111\u1ed1i s\u1ed1 v\u1ecb tr\u00ed v\u00e0 \u0111\u1ed1i s\u1ed1 t\u1eeb kh\u00f3a (th\u01b0\u1eddng th\u00ec \u0111\u1ed1i s\u1ed1 v\u1ecb tr\u00ed ph\u1ea3i \u0111\u1ee9ng tr\u01b0\u1edbc). \u0110\u00e2y l\u00e0 m\u1ed9t t\u00ednh n\u0103ng m\u1ea1nh m\u1ebd gi\u00fap code Python tr\u1edf n\u00ean linh ho\u1ea1t v\u00e0 d\u1ec5 \u0111\u1ecdc.<\/p>\n<div style=\"background-color: #e6f2ff; border-radius: 10px; padding: 20px; margin: 20px 0; border: 1px solid #b3d9ff;\">\n<p><strong>C\u00d3 TH\u1ec2 B\u1ea0N QUAN T\u00c2M:<\/strong><\/p>\n<p>Khi \u0111\u00e3 hi\u1ec3u r\u00f5 v\u1ec1 tham s\u1ed1 v\u00e0 s\u1eb5n s\u00e0ng x\u00e2y d\u1ef1ng nh\u1eefng d\u1ef1 \u00e1n l\u1eadp tr\u00ecnh th\u1ef1c t\u1ebf, b\u1ea1n s\u1ebd c\u1ea7n m\u1ed9t m\u00f4i tr\u01b0\u1eddng m\u1ea1nh m\u1ebd, \u1ed5n \u0111\u1ecbnh \u0111\u1ec3 tri\u1ec3n khai. Kh\u00e1m ph\u00e1 ngay <strong><a target=\"_blank\" rel=\"noopener noreferrer\" href=\"https:\/\/interdata.vn\/thue-vps\/\">d\u1ecbch v\u1ee5 thu\u00ea VPS gi\u00e1 r\u1ebb &#8211; uy t\u00edn &#8211; t\u1ed1c \u0111\u1ed9 cao<\/a><\/strong> t\u1ea1i InterData ch\u1ec9 t\u1eeb 3K\/ng\u00e0y, s\u1eed d\u1ee5ng ph\u1ea7n c\u1ee9ng chuy\u00ean d\u1ee5ng <a href=\"https:\/\/interdata.vn\/blog\/cpu-amd-epyc\/\">AMD EPYC<\/a> Gen 3th v\u00e0 SSD NVMe U.2 cho hi\u1ec7u n\u0103ng v\u01b0\u1ee3t tr\u1ed9i, c\u00f9ng <a href=\"https:\/\/interdata.vn\/blog\/bang-thong-la-gi\/\">b\u0103ng th\u00f4ng<\/a> cao.<\/p>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"Cac-loai-Tham-so-thuong-gap-trong-lap-trinh\"><\/span>C\u00e1c lo\u1ea1i Tham s\u1ed1 th\u01b0\u1eddng g\u1eb7p trong l\u1eadp tr\u00ecnh<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>D\u1ef1a tr\u00ean c\u00e1ch ch\u00fang \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a v\u00e0 s\u1eed d\u1ee5ng, c\u00f3 th\u1ec3 ph\u00e2n lo\u1ea1i tham s\u1ed1 th\u00e0nh m\u1ed9t s\u1ed1 lo\u1ea1i ch\u00ednh:<\/p>\n<ol>\n<li><strong>Tham s\u1ed1 v\u1ecb tr\u00ed (Positional Parameters):<\/strong> Nh\u01b0 \u0111\u00e3 gi\u1ea3i th\u00edch, gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c g\u00e1n d\u1ef1a tr\u00ean th\u1ee9 t\u1ef1. \u0110\u00e2y l\u00e0 lo\u1ea1i ph\u1ed5 bi\u1ebfn nh\u1ea5t.<\/li>\n<li><strong>Tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh (Default Parameters):<\/strong> C\u00f3 gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c \u0111\u1ecbnh s\u1eb5n n\u1ebfu kh\u00f4ng c\u00f3 \u0111\u1ed1i s\u1ed1 n\u00e0o \u0111\u01b0\u1ee3c cung c\u1ea5p khi g\u1ecdi h\u00e0m.<\/li>\n<li><strong>Tham s\u1ed1 t\u1eeb kh\u00f3a (Keyword Parameters):<\/strong> (Ch\u1ee7 y\u1ebfu trong Python) Cho ph\u00e9p truy\u1ec1n \u0111\u1ed1i s\u1ed1 b\u1eb1ng c\u00e1ch ch\u1ec9 \u0111\u1ecbnh t\u00ean tham s\u1ed1, kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o v\u1ecb tr\u00ed.<\/li>\n<li><strong>(N\u00e2ng cao) Tham s\u1ed1 t\u00f9y ch\u1ecdn\/bi\u1ebfn \u0111\u1ed5i (Variable-length Parameters):<\/strong> Cho ph\u00e9p h\u00e0m nh\u1eadn m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng \u0111\u1ed1i s\u1ed1 kh\u00f4ng x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc.\n<ul>\n<li>Trong Python: <code>*args<\/code> (nh\u1eadn c\u00e1c \u0111\u1ed1i s\u1ed1 v\u1ecb tr\u00ed d\u01b0 th\u1eeba th\u00e0nh m\u1ed9t tuple) v\u00e0 <code>**kwargs<\/code> (nh\u1eadn c\u00e1c \u0111\u1ed1i s\u1ed1 t\u1eeb kh\u00f3a d\u01b0 th\u1eeba th\u00e0nh m\u1ed9t dictionary).<\/li>\n<li>Trong JavaScript: \u0110\u1ed1i t\u01b0\u1ee3ng <code>arguments<\/code> (c\u0169) ho\u1eb7c s\u1eed d\u1ee5ng rest parameter <code>...tenBien<\/code> (ES6+).<\/li>\n<li><i>V\u00ed d\u1ee5 Python:<\/i>Python\n<pre><code class=\"language-plaintext\">def tinh_tong_nhieu_so(*args): # args l\u00e0 m\u1ed9t tuple ch\u1ee9a c\u00e1c \u0111\u1ed1i s\u1ed1 v\u1ecb tr\u00ed\r\n  tong = 0\r\n  for so in args:\r\n    tong += so\r\n  return tong\r\n\r\nprint(tinh_tong_nhieu_so(1, 2, 3)) # Output: 6\r\nprint(tinh_tong_nhieu_so(5, 10, 15, 20)) # Output: 50\r\n<\/code><\/pre>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p>Vi\u1ec7c hi\u1ec3u c\u00e1c lo\u1ea1i tham s\u1ed1 n\u00e0y gi\u00fap b\u1ea1n \u0111\u1ecdc hi\u1ec3u t\u00e0i li\u1ec7u (documentation) c\u1ee7a c\u00e1c th\u01b0 vi\u1ec7n, <a href=\"https:\/\/interdata.vn\/blog\/framework-la-gi\/\">framework<\/a> v\u00e0 vi\u1ebft c\u00e1c h\u00e0m linh ho\u1ea1t h\u01a1n.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-02.jpg\" alt=\"Tham s\u1ed1 (Parameter) 02\" width=\"750\" height=\"404\" class=\"aligncenter size-full wp-image-27492\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-02.jpg 750w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/04\/Tham-so-Parameter-02-300x162.jpg 300w\" sizes=\"auto, (max-width: 750px) 100vw, 750px\" \/><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Moi-lien-he-giua-Tham-so-va-Pham-vi-bien-Variable-Scope\"><\/span>M\u1ed1i li\u00ean h\u1ec7 gi\u1eefa Tham s\u1ed1 v\u00e0 Ph\u1ea1m vi bi\u1ebfn (Variable Scope)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>M\u1ed9t \u0111i\u1ec3m quan tr\u1ecdng c\u1ea7n n\u1eafm v\u1eefng l\u00e0 <strong>ph\u1ea1m vi (scope)<\/strong> c\u1ee7a tham s\u1ed1. Khi m\u1ed9t h\u00e0m \u0111\u01b0\u1ee3c g\u1ecdi v\u00e0 c\u00e1c \u0111\u1ed1i s\u1ed1 \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o, c\u00e1c bi\u1ebfn tham s\u1ed1 t\u01b0\u01a1ng \u1ee9ng s\u1ebd \u0111\u01b0\u1ee3c t\u1ea1o ra <strong>b\u00ean trong<\/strong> h\u00e0m \u0111\u00f3. Ch\u00fang \u0111\u01b0\u1ee3c coi l\u00e0 <strong>bi\u1ebfn c\u1ee5c b\u1ed9 (local variables)<\/strong> c\u1ee7a h\u00e0m.<\/p>\n<p>\u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0:<\/p>\n<ul>\n<li>Tham s\u1ed1 ch\u1ec9 t\u1ed3n t\u1ea1i v\u00e0 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c truy c\u1eadp <strong>b\u00ean trong<\/strong> th\u00e2n h\u00e0m (kh\u1ed1i l\u1ec7nh c\u1ee7a h\u00e0m) m\u00e0 n\u00f3 \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a.<\/li>\n<li>Khi h\u00e0m k\u1ebft th\u00fac th\u1ef1c thi, c\u00e1c bi\u1ebfn tham s\u1ed1 n\u00e0y s\u1ebd b\u1ecb h\u1ee7y v\u00e0 gi\u1ea3i ph\u00f3ng kh\u1ecfi b\u1ed9 nh\u1edb.<\/li>\n<li>M\u00e3 ngu\u1ed3n b\u00ean ngo\u00e0i h\u00e0m kh\u00f4ng th\u1ec3 truy c\u1eadp tr\u1ef1c ti\u1ebfp v\u00e0o c\u00e1c bi\u1ebfn tham s\u1ed1 c\u1ee7a h\u00e0m \u0111\u00f3.<\/li>\n<\/ul>\n<p>H\u00e3y xem v\u00ed d\u1ee5:<\/p>\n<p>Python<\/p>\n<pre><code class=\"language-plaintext\">def cong_hai_so(a, b): # a v\u00e0 b l\u00e0 tham s\u1ed1 (bi\u1ebfn c\u1ee5c b\u1ed9)\r\n  ket_qua_cuc_bo = a + b\r\n  print(f\"B\u00ean trong h\u00e0m: a={a}, b={b}, k\u1ebft qu\u1ea3={ket_qua_cuc_bo}\")\r\n  return ket_qua_cuc_bo\r\n\r\nso_1 = 5\r\nso_2 = 10\r\ntong = cong_hai_so(so_1, so_2) # G\u1ecdi h\u00e0m\r\n\r\nprint(f\"B\u00ean ngo\u00e0i h\u00e0m: so_1={so_1}, so_2={so_2}, t\u1ed5ng={tong}\")\r\n\r\n# Th\u1eed truy c\u1eadp bi\u1ebfn tham s\u1ed1 'a' ho\u1eb7c 'ket_qua_cuc_bo' t\u1eeb b\u00ean ngo\u00e0i =&gt; G\u00e2y l\u1ed7i!\r\n# print(a) # NameError: name 'a' is not defined\r\n# print(ket_qua_cuc_bo) # NameError: name 'ket_qua_cuc_bo' is not defined\r\n<\/code><\/pre>\n<p>V\u00ed d\u1ee5 tr\u00ean cho th\u1ea5y <code>a<\/code>, <code>b<\/code> v\u00e0 <code>ket_qua_cuc_bo<\/code> ch\u1ec9 t\u1ed3n t\u1ea1i trong h\u00e0m <code>cong_hai_so<\/code>. B\u00ean ngo\u00e0i h\u00e0m, ch\u00fang kh\u00f4ng \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a. Ng\u01b0\u1ee3c l\u1ea1i, c\u00e1c bi\u1ebfn <code>so_1<\/code>, <code>so_2<\/code>, <code>tong<\/code> \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a b\u00ean ngo\u00e0i v\u00e0 c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 truy\u1ec1n gi\u00e1 tr\u1ecb (d\u01b0\u1edbi d\u1ea1ng \u0111\u1ed1i s\u1ed1) v\u00e0o h\u00e0m.<\/p>\n<p>Hi\u1ec3u v\u1ec1 ph\u1ea1m vi c\u1ee5c b\u1ed9 c\u1ee7a tham s\u1ed1 gi\u00fap tr\u00e1nh xung \u0111\u1ed9t t\u00ean bi\u1ebfn v\u00e0 qu\u1ea3n l\u00fd tr\u1ea1ng th\u00e1i ch\u01b0\u01a1ng tr\u00ecnh hi\u1ec7u qu\u1ea3 h\u01a1n.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Luu-y-quan-trong-khi-lam-viec-voi-Tham-so\"><\/span>L\u01b0u \u00fd quan tr\u1ecdng khi l\u00e0m vi\u1ec7c v\u1edbi Tham s\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>S\u1eed d\u1ee5ng tham s\u1ed1 \u0111\u00fang c\u00e1ch gi\u00fap code c\u1ee7a b\u1ea1n s\u1ea1ch s\u1ebd, d\u1ec5 hi\u1ec3u v\u00e0 d\u1ec5 b\u1ea3o tr\u00ec h\u01a1n. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t v\u00e0i l\u1eddi khuy\u00ean v\u00e0 th\u1ef1c h\u00e0nh t\u1ed1t (best practices):<\/p>\n<ol>\n<li><strong>\u0110\u1eb7t t\u00ean tham s\u1ed1 r\u00f5 r\u00e0ng, g\u1ee3i \u00fd:<\/strong> T\u00ean tham s\u1ed1 n\u00ean m\u00f4 t\u1ea3 r\u00f5 r\u00e0ng m\u1ee5c \u0111\u00edch ho\u1eb7c \u00fd ngh\u0129a c\u1ee7a d\u1eef li\u1ec7u m\u00e0 n\u00f3 \u0111\u1ea1i di\u1ec7n. Tr\u00e1nh c\u00e1c t\u00ean m\u01a1 h\u1ed3 nh\u01b0 <code>x<\/code>, <code>y<\/code>, <code>data<\/code> n\u1ebfu c\u00f3 th\u1ec3. V\u00ed d\u1ee5: <code>user_name<\/code>, <code>item_price<\/code>, <code>max_retries<\/code> t\u1ed1t h\u01a1n nhi\u1ec1u so v\u1edbi <code>un<\/code>, <code>ip<\/code>, <code>mr<\/code>. Tu\u00e2n th\u1ee7 quy \u01b0\u1edbc \u0111\u1eb7t t\u00ean c\u1ee7a ng\u00f4n ng\u1eef (snake_case cho Python, camelCase cho JavaScript).<\/li>\n<li><strong>Tr\u00e1nh qu\u00e1 nhi\u1ec1u tham s\u1ed1:<\/strong> M\u1ed9t h\u00e0m c\u00f3 qu\u00e1 nhi\u1ec1u tham s\u1ed1 (th\u01b0\u1eddng &gt; 4 ho\u1eb7c 5) c\u00f3 th\u1ec3 l\u00e0 d\u1ea5u hi\u1ec7u cho th\u1ea5y h\u00e0m \u0111\u00f3 \u0111ang l\u00e0m qu\u00e1 nhi\u1ec1u vi\u1ec7c ho\u1eb7c thi\u1ebft k\u1ebf ch\u01b0a t\u1ed1i \u01b0u. N\u00f3 c\u0169ng l\u00e0m cho vi\u1ec7c g\u1ecdi h\u00e0m tr\u1edf n\u00ean ph\u1ee9c t\u1ea1p. C\u00e2n nh\u1eafc nh\u00f3m c\u00e1c tham s\u1ed1 li\u00ean quan v\u00e0o m\u1ed9t \u0111\u1ed1i t\u01b0\u1ee3ng (object), dictionary, ho\u1eb7c struct v\u00e0 truy\u1ec1n \u0111\u1ed1i t\u01b0\u1ee3ng \u0111\u00f3 nh\u01b0 m\u1ed9t tham s\u1ed1 duy nh\u1ea5t.<\/li>\n<li><strong>Ki\u1ec3m tra t\u00ednh h\u1ee3p l\u1ec7 c\u1ee7a \u0111\u1ed1i s\u1ed1 (Argument Validation):<\/strong> \u0110\u1eb7c bi\u1ec7t khi d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o \u0111\u1ebfn t\u1eeb ng\u01b0\u1eddi d\u00f9ng ho\u1eb7c ngu\u1ed3n kh\u00f4ng \u0111\u00e1ng tin c\u1eady, b\u1ea1n n\u00ean ki\u1ec3m tra c\u00e1c \u0111\u1ed1i s\u1ed1 \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o b\u00ean trong h\u00e0m. Ki\u1ec3m tra xem ch\u00fang c\u00f3 \u0111\u00fang ki\u1ec3u d\u1eef li\u1ec7u mong \u0111\u1ee3i kh\u00f4ng, c\u00f3 n\u1eb1m trong ph\u1ea1m vi gi\u00e1 tr\u1ecb h\u1ee3p l\u1ec7 kh\u00f4ng, v.v. \u0110i\u1ec1u n\u00e0y gi\u00fap h\u00e0m ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh v\u00e0 tr\u00e1nh c\u00e1c l\u1ed7i kh\u00f4ng mong mu\u1ed1n.<\/li>\n<li><strong>S\u1eed d\u1ee5ng tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh m\u1ed9t c\u00e1ch h\u1ee3p l\u00fd:<\/strong> Tham s\u1ed1 m\u1eb7c \u0111\u1ecbnh r\u1ea5t ti\u1ec7n l\u1ee3i, nh\u01b0ng h\u00e3y \u0111\u1ea3m b\u1ea3o gi\u00e1 tr\u1ecb m\u1eb7c \u0111\u1ecbnh l\u00e0 gi\u00e1 tr\u1ecb ph\u1ed5 bi\u1ebfn nh\u1ea5t ho\u1eb7c an to\u00e0n nh\u1ea5t. \u0110\u1eebng l\u1ea1m d\u1ee5ng ch\u00fang cho m\u1ecdi tham s\u1ed1.<\/li>\n<li><strong>Hi\u1ec3u r\u00f5 c\u01a1 ch\u1ebf truy\u1ec1n tham s\u1ed1 (Pass by Value vs Pass by Reference):<\/strong> C\u00e1ch \u0111\u1ed1i s\u1ed1 \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o tham s\u1ed1 (truy\u1ec1n gi\u00e1 tr\u1ecb hay truy\u1ec1n tham chi\u1ebfu) kh\u00e1c nhau gi\u1eefa c\u00e1c ng\u00f4n ng\u1eef v\u00e0 ki\u1ec3u d\u1eef li\u1ec7u. Hi\u1ec3u r\u00f5 \u0111i\u1ec1u n\u00e0y r\u1ea5t quan tr\u1ecdng \u0111\u1ec3 tr\u00e1nh c\u00e1c hi\u1ec7u \u1ee9ng ph\u1ee5 kh\u00f4ng mong mu\u1ed1n, \u0111\u1eb7c bi\u1ec7t khi l\u00e0m vi\u1ec7c v\u1edbi c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng c\u00f3 th\u1ec3 thay \u0111\u1ed5i (mutable objects) nh\u01b0 list trong Python hay object trong JavaScript. (Ch\u1ee7 \u0111\u1ec1 n\u00e0y ph\u1ee9c t\u1ea1p h\u01a1n v\u00e0 th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp trong c\u00e1c b\u00e0i vi\u1ebft chuy\u00ean s\u00e2u h\u01a1n).<\/li>\n<\/ol>\n<p>Vi\u1ec7c \u00e1p d\u1ee5ng nh\u1eefng l\u01b0u \u00fd n\u00e0y s\u1ebd gi\u00fap b\u1ea1n vi\u1ebft code kh\u00f4ng ch\u1ec9 ch\u1ea1y \u0111\u00fang m\u00e0 c\u00f2n chuy\u00ean nghi\u1ec7p v\u00e0 d\u1ec5 d\u00e0ng l\u00e0m vi\u1ec7c nh\u00f3m h\u01a1n.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cau-hoi-thuong-gap-ve-Tham-so-FAQ\"><\/span>C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p v\u1ec1 Tham s\u1ed1 (FAQ)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p m\u00e0 ng\u01b0\u1eddi m\u1edbi b\u1eaft \u0111\u1ea7u hay th\u1eafc m\u1eafc v\u1ec1 tham s\u1ed1:<\/p>\n<p><strong>1. Tham s\u1ed1 v\u00e0 \u0111\u1ed1i s\u1ed1 kh\u00e1c nhau th\u1ebf n\u00e0o? (T\u00f3m t\u1eaft)<\/strong><\/p>\n<ul>\n<li><strong>Tham s\u1ed1 (Parameter)<\/strong> l\u00e0 bi\u1ebfn \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong <i>khai b\u00e1o<\/i> h\u00e0m, \u0111\u00f3ng vai tr\u00f2 nh\u01b0 t\u00ean gi\u1eef ch\u1ed7.<\/li>\n<li><strong>\u0110\u1ed1i s\u1ed1 (Argument)<\/strong> l\u00e0 gi\u00e1 tr\u1ecb <i>th\u1ef1c t\u1ebf<\/i> \u0111\u01b0\u1ee3c truy\u1ec1n v\u00e0o khi <i>g\u1ecdi<\/i> h\u00e0m, cung c\u1ea5p d\u1eef li\u1ec7u cho tham s\u1ed1.<\/li>\n<\/ul>\n<p><strong>2. Tham s\u1ed1 c\u00f3 ph\u1ea3i l\u00e0 bi\u1ebfn kh\u00f4ng?<\/strong><\/p>\n<ul>\n<li>C\u00f3. Tham s\u1ed1 v\u1ec1 c\u01a1 b\u1ea3n l\u00e0 m\u1ed9t <strong>bi\u1ebfn c\u1ee5c b\u1ed9 (local variable)<\/strong> \u0111\u1eb7c bi\u1ec7t, ch\u1ec9 t\u1ed3n t\u1ea1i v\u00e0 ho\u1ea1t \u0111\u1ed9ng b\u00ean trong ph\u1ea1m vi c\u1ee7a h\u00e0m ho\u1eb7c ph\u01b0\u01a1ng th\u1ee9c m\u00e0 n\u00f3 \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a.<\/li>\n<\/ul>\n<p><strong>3. M\u1ed9t h\u00e0m c\u00f3 th\u1ec3 kh\u00f4ng c\u00f3 tham s\u1ed1 kh\u00f4ng?<\/strong><\/p>\n<ul>\n<li>Ho\u00e0n to\u00e0n c\u00f3 th\u1ec3. M\u1ed9t h\u00e0m kh\u00f4ng c\u00f3 tham s\u1ed1 th\u01b0\u1eddng th\u1ef1c hi\u1ec7n m\u1ed9t c\u00f4ng vi\u1ec7c c\u1ed1 \u0111\u1ecbnh ho\u1eb7c l\u1ea5y d\u1eef li\u1ec7u t\u1eeb c\u00e1c ngu\u1ed3n kh\u00e1c (v\u00ed d\u1ee5: bi\u1ebfn to\u00e0n c\u1ee5c, \u0111\u1ecdc file). V\u00ed d\u1ee5:Python\n<pre><code class=\"language-plaintext\">def in_loi_chao_co_dinh():\r\n  print(\"Ch\u00e0o m\u1eebng b\u1ea1n!\")\r\n\r\nin_loi_chao_co_dinh() # G\u1ecdi h\u00e0m kh\u00f4ng c\u1ea7n \u0111\u1ed1i s\u1ed1\r\n<\/code><\/pre>\n<\/li>\n<\/ul>\n<p><strong>4. \u0110\u1eb7t t\u00ean tham s\u1ed1 c\u00f3 quan tr\u1ecdng kh\u00f4ng?<\/strong><\/p>\n<ul>\n<li>R\u1ea5t quan tr\u1ecdng! T\u00ean tham s\u1ed1 r\u00f5 r\u00e0ng, g\u1ee3i nh\u1edb gi\u00fap ng\u01b0\u1eddi \u0111\u1ecdc (bao g\u1ed3m c\u1ea3 ch\u00ednh b\u1ea1n trong t\u01b0\u01a1ng lai) hi\u1ec3u \u0111\u01b0\u1ee3c m\u1ee5c \u0111\u00edch c\u1ee7a h\u00e0m v\u00e0 c\u00e1ch s\u1eed d\u1ee5ng n\u00f3 m\u00e0 kh\u00f4ng c\u1ea7n \u0111\u1ecdc k\u1ef9 ph\u1ea7n logic b\u00ean trong. \u0110\u00e2y l\u00e0 m\u1ed9t ph\u1ea7n quan tr\u1ecdng c\u1ee7a vi\u1ec7c vi\u1ebft code &#8220;s\u1ea1ch&#8221; (clean code).<\/li>\n<\/ul>\n<p><strong>5. Th\u1ee9 t\u1ef1 tham s\u1ed1 c\u00f3 quan tr\u1ecdng kh\u00f4ng?<\/strong><\/p>\n<ul>\n<li>C\u00f3, \u0111\u1ed1i v\u1edbi <strong>tham s\u1ed1 v\u1ecb tr\u00ed<\/strong>. Th\u1ee9 t\u1ef1 \u0111\u1ed1i s\u1ed1 truy\u1ec1n v\u00e0o ph\u1ea3i kh\u1edbp v\u1edbi th\u1ee9 t\u1ef1 tham s\u1ed1 khai b\u00e1o.<\/li>\n<li>Kh\u00f4ng quan tr\u1ecdng \u0111\u1ed1i v\u1edbi <strong>tham s\u1ed1 t\u1eeb kh\u00f3a<\/strong> (nh\u01b0 trong Python) v\u00ec b\u1ea1n ch\u1ec9 \u0111\u1ecbnh r\u00f5 t\u00ean tham s\u1ed1 khi truy\u1ec1n gi\u00e1 tr\u1ecb.<\/li>\n<\/ul>\n<hr \/>\n<p>Qua b\u00e0i vi\u1ebft n\u00e0y, hy v\u1ecdng b\u1ea1n \u0111\u00e3 c\u00f3 c\u00e1i nh\u00ecn r\u00f5 r\u00e0ng v\u00e0 \u0111\u1ea7y \u0111\u1ee7 v\u1ec1 <strong>tham s\u1ed1 (parameter) l\u00e0 g\u00ec<\/strong> trong l\u1eadp tr\u00ecnh. Ch\u00fang kh\u00f4ng ch\u1ec9 l\u00e0 nh\u1eefng bi\u1ebfn \u0111\u01a1n thu\u1ea7n m\u00e0 l\u00e0 c\u00f4ng c\u1ee5 thi\u1ebft y\u1ebfu gi\u00fap ch\u00fang ta x\u00e2y d\u1ef1ng c\u00e1c h\u00e0m v\u00e0 ph\u01b0\u01a1ng th\u1ee9c linh ho\u1ea1t, m\u1ea1nh m\u1ebd v\u00e0 c\u00f3 kh\u1ea3 n\u0103ng t\u00e1i s\u1eed d\u1ee5ng cao.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tham s\u1ed1 (parameter) l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m n\u1ec1n t\u1ea3ng, kh\u00f4ng th\u1ec3 thi\u1ebfu \u0111\u1ec3 vi\u1ebft code linh ho\u1ea1t v\u00e0 hi\u1ec7u qu\u1ea3 trong m\u1ecdi ng\u00f4n ng\u1eef l\u1eadp tr\u00ecnh. B\u00e0i vi\u1ebft n\u00e0y s\u1ebd d\u1eabn d\u1eaft b\u1ea1n t\u00ecm hi\u1ec3u t\u1eeb A-Z v\u1ec1 ch\u1ee7 \u0111\u1ec1 n\u00e0y: t\u1eeb \u0111\u1ecbnh ngh\u0129a c\u1ed1t l\u00f5i, l\u00fd do c\u1ea7n thi\u1ebft, s\u1ef1 kh\u00e1c bi\u1ec7t m\u1ea5u ch\u1ed1t<\/p>\n","protected":false},"author":2,"featured_media":27493,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[140],"tags":[],"class_list":["post-27487","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-lap-trinh"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/27487","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=27487"}],"version-history":[{"count":4,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/27487\/revisions"}],"predecessor-version":[{"id":27496,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/27487\/revisions\/27496"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/27493"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=27487"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=27487"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=27487"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}