{"id":14431,"date":"2021-09-02T08:50:52","date_gmt":"2021-09-02T08:50:52","guid":{"rendered":"https:\/\/freehost.page\/?p=14431"},"modified":"2021-09-02T08:50:52","modified_gmt":"2021-09-02T08:50:52","slug":"thuc-hanh-viet-ham-trong-javascript","status":"publish","type":"post","link":"https:\/\/kiencang.net\/thuc-hanh-viet-ham-trong-javascript\/","title":{"rendered":"Th\u1ef1c h\u00e0nh vi\u1ebft h\u00e0m trong JavaScript"},"content":{"rendered":"\n<p>H\u00f4m nay ch\u00fang ta s\u1ebd th\u1ef1c h\u00e0nh vi\u1ebft c\u00e1c h\u00e0m JS \u0111\u01a1n gi\u1ea3n, qua \u0111\u00f3 s\u1ebd c\u1ea3i thi\u1ec7n d\u1ea7n kh\u1ea3 n\u0103ng t\u1ea1o c\u00e1c h\u00e0m ph\u1ee9c t\u1ea1p h\u01a1n.<\/p>\n\n\n\n<p><strong>B\u00e0i to\u00e1n 1: nh\u1eadp v\u00e0o ba s\u1ed1 ch\u1ec9 \u0111\u1ed9 d\u00e0i, h\u00e3y xem n\u00f3 c\u00f3 ph\u1ea3i l\u00e0 ba \u0111\u1ed9 d\u00e0i c\u1ee7a m\u1ed9t c\u1ea1nh tam gi\u00e1c kh\u00f4ng?<\/strong><\/p>\n\n\n\n<p>C\u00e1ch gi\u1ea3i: ba \u0111\u1ed9 d\u00e0i a, b, c ch\u1ec9 t\u1ea1o \u0111\u01b0\u1ee3c th\u00e0nh h\u00ecnh tam gi\u00e1c n\u1ebfu ba \u0111i\u1ec1u ki\u1ec7n sau \u0111\u1ed3ng th\u1eddi th\u1ecfa m\u00e3n:<\/p>\n\n\n\n<ul><li>a + b &gt; c<\/li><li>b + c &gt; a<\/li><li>a + c &gt; b<\/li><\/ul>\n\n\n\n<p>Nh\u01b0 v\u1eady ch\u00fang ta s\u1ebd s\u1eed d\u1ee5ng \u0111\u1ebfn c\u00e2u l\u1ec7nh <code>if<\/code> v\u00e0 to\u00e1n t\u1eed <code>&amp;&amp;<\/code><\/p>\n\n\n\n<p>Bi\u1ebfn \u0111\u1ea7u v\u00e0o s\u1ebd l\u00e0 3 \u0111\u1ed9 d\u00e0i tr\u00ean.<\/p>\n\n\n\n<p>H\u00e0m c\u1ee5 th\u1ec3:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n        \n&lt;script&gt;\n   function triAngle(a, b, c) {\n         if (((a + b) &gt; c) &amp;&amp; ((b + c) &gt; a) &amp;&amp; ((a + c) &gt; b)) {\n                                        x = \"TRUE\";\n         }\n         else { x = \"FALSE\";}\n    return x;              \n    }\n\n    document.getElementById(\"demo\").innerHTML = triAngle(2, 3, 4);\n&lt;\/script&gt; <\/code><\/pre>\n\n\n\n<p>Nh\u01b0ng \u0111o\u1ea1n m\u00e3 tr\u00ean c\u00f3 l\u1ed7 h\u1ed5ng. N\u00f3 kh\u00f4ng \u0111\u00e1nh gi\u00e1 d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o, v\u00ec th\u1ebf k\u1ebft qu\u1ea3 c\u1ee7a<code> triAngle(\"a\", 3, 4)<\/code> th\u00ec l\u1ea1i l\u00e0 <code>FALSE<\/code>. K\u1ebft qu\u1ea3 False th\u00ec c\u0169ng kh\u00f4ng sai nh\u01b0ng ch\u01b0a ho\u00e0n to\u00e0n ch\u00ednh x\u00e1c.<\/p>\n\n\n\n<p>Ch\u00fang ta s\u1ebd b\u1ed5 sung m\u00e3 \u0111\u1ec3 x\u00e1c nh\u1eadn d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o l\u00e0 h\u1ee3p l\u1ec7. \u1ede \u0111\u00e2y d\u1eef li\u1ec7u h\u1ee3p l\u1ec7 l\u00e0 d\u1ea1ng s\u1ed1. T\u1ee9c l\u00e0 c\u1ea3 3 bi\u1ebfn \u0111\u1ea7u v\u00e0o a, b, c ph\u1ea3i l\u00e0 s\u1ed1 c\u1ea3 th\u00ec m\u1edbi \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n<p>Ch\u00fang ta s\u1ebd d\u00f9ng h\u00e0m <code>isNaN()<\/code> \u0111\u1ec3 bi\u1ebft d\u1eef li\u1ec7u c\u00f3 ph\u1ea3i l\u00e0 s\u1ed1 kh\u00f4ng, v\u1edbi h\u00e0m n\u00e0y, n\u1ebfu kh\u00f4ng ph\u1ea3i l\u00e0 s\u1ed1 n\u00f3 s\u1ebd tr\u1ea3 v\u1ec1 <code>TRUE<\/code>, c\u00f2n n\u1ebfu l\u00e0 s\u1ed1 n\u00f3 s\u1ebd tr\u1ea3 v\u1ec1 <code>FALSE<\/code>. Ta s\u1ebd d\u00f9ng to\u00e1n t\u1eed ph\u1ee7 \u0111\u1ecbnh <code>!<\/code> \u0111\u1ec3 \u0111\u1ea3o l\u1ea1i cho ti\u1ec7n t\u01b0 duy t\u1ee9c l\u00e0 <code>!isNaN(x)<\/code> s\u1ebd l\u00e0 <code>TRUE<\/code> n\u1ebfu x l\u00e0 s\u1ed1.<\/p>\n\n\n\n<p>Do v\u1eady \u0111o\u1ea1n m\u00e3 x\u00e1c th\u1ef1c d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o s\u1ebd ki\u1ec3u th\u1ebf n\u00e0y:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>if (!isNaN(a) &amp;&amp; !isNaN(b) &amp;&amp; !isNaN(c)) \/\/ t\u1ee9c l\u00e0 c\u1ea3 3 ph\u1ea3i l\u00e0 s\u1ed1 n\u00f3 m\u1edbi tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 TRUE.<\/code><\/pre>\n\n\n\n<p>\u0110o\u1ea1n m\u00e3 \u0111\u1ea7y \u0111\u1ee7 s\u1ebd th\u1ebf n\u00e0y:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n        \n&lt;script&gt;\n   function triAngle(a, b, c) {\n         if (!isNaN(a) &amp;&amp; !isNaN(b) &amp;&amp; !isNaN(c)) {\n\n               if (((a + b) &gt; c) &amp;&amp; ((b + c) &gt; a) &amp;&amp; ((a + c) &gt; b)) {\n                                              x = \"TRUE\";\n               }\n               else { x = \"FALSE\";}\n         }\n         else {\n            x = \"KKK\";\n         }\n   return x;              \n   }\n\n    document.getElementById(\"demo\").innerHTML = triAngle(\"a\", 3, 4);\n&lt;\/script&gt;<\/code><\/pre>\n\n\n\n<p>N\u1ebfu d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o kh\u00f4ng h\u1ee3p l\u1ec7 n\u00f3 s\u1ebd xu\u1ea5t ra gi\u00e1 tr\u1ecb <code>KKK<\/code> ra m\u00e0n h\u00ecnh.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>B\u00e0i to\u00e1n 2: M\u1ed9t m\u1ea3ng g\u1ed3m 10 s\u1ed1 t\u1eeb 0 t\u1edbi 9, show ra 3 s\u1ed1 ng\u1eabu nhi\u00ean nh\u01b0ng kh\u00f4ng \u0111\u01b0\u1ee3c tr\u00f9ng nhau. T\u1ee9c l\u00e0 1, 5, 7 th\u00ec \u0111\u01b0\u1ee3c, nh\u01b0ng 3, 2, 3 s\u1ebd kh\u00f4ng \u0111\u1ea1t y\u00eau c\u1ea7u.<\/strong><\/p>\n\n\n\n<p>C\u00f3 hai h\u00e0m trong JS s\u1ebd gi\u00fap ta l\u00e0m vi\u1ec7c n\u00e0y:<\/p>\n\n\n\n<ul><li>H\u00e0m <code>Math.floor(Math.random() * 10);<\/code> s\u1ebd t\u1ea1o ra gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean t\u1eeb 0 t\u1edbi 9;<\/li><li>H\u00e0m <code>[\u2026new Set(ranDom)];<\/code> s\u1ebd lo\u1ea1i b\u1ecf c\u00e1c ph\u1ea7n t\u1eed tr\u00f9ng nhau trong m\u1ea3ng;<\/li><\/ul>\n\n\n\n<p>\u00dd t\u01b0\u1edfng \u1edf \u0111\u00e2y l\u00e0 ta t\u1ea1o m\u1ed9t gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean, r\u1ed3i \u0111\u01b0a n\u00f3 v\u00e0o m\u1ea3ng, v\u00ec y\u00eau c\u1ea7u tr\u00e1nh tr\u00f9ng l\u1eb7p ta d\u00f9ng h\u00e0m th\u1ee9 hai \u0111\u1ec3 lo\u1ea1i tr\u00f9ng. Sau \u0111\u00f3 ta \u0111\u1ebfm s\u1ed1 ph\u1ea7n t\u1eed c\u1ee7a m\u1ea3ng \u0111\u00e3 b\u1ecf tr\u00f9ng, \u0111\u1ea1t \u0111\u1ebfn s\u1ed1 l\u01b0\u1ee3ng 3 l\u00e0 \u0111\u1ea1t y\u00eau c\u1ea7u.<\/p>\n\n\n\n<p>V\u1eady \u1edf tr\u00ean l\u00e0 v\u00f2ng l\u1eb7p c\u00f3 \u0111i\u1ec1u ki\u1ec7n, \u0111i\u1ec1u ki\u1ec7n \u1edf \u0111\u00e2y l\u00e0 s\u1ed1 l\u01b0\u1ee3ng \u0111\u1ea1t 3, c\u00f2n v\u00f2ng l\u1eb7p l\u00e0 c\u1ee9 t\u1ea1o ra gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean, \u0111\u01b0a v\u00e0o m\u1ea3ng, r\u1ed3i lo\u1ea1i tr\u00f9ng. V\u1eady ch\u00fang ta c\u1ea7n d\u00f9ng th\u00eam h\u00e0m <code>while<\/code> \u0111\u1ec3 t\u1ea1o ra v\u00f2ng l\u1eb7p c\u00f3 \u0111i\u1ec1u ki\u1ec7n.<\/p>\n\n\n\n<p>C\u00e2u l\u1ec7nh ho\u00e0n ch\u1ec9nh s\u1ebd nh\u01b0 sau. K\u1ebft qu\u1ea3 tr\u1ea3 v\u1ec1 s\u1ebd g\u1ed3m m\u1ea3ng g\u1ed3m ba s\u1ed1 t\u1eeb 0 \u0111\u1ebfn 9 v\u00e0 kh\u00f4ng tr\u00f9ng nhau.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n\n&lt;script&gt;\n\nfunction random3() {\n   let i = 0; \n   ranDom = &#91;]; \/\/ m\u1ea3ng ch\u1ee9a gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean\n   uniqueNums = &#91;]; \/\/ m\u1ea3ng lo\u1ea1i b\u1ecf tr\u00f9ng l\u1eb7p\n   while (i &lt; 3) {\n       ranDom&#91;i] = Math.floor(Math.random() * 10); \/\/ l\u1ea5y gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean t\u1eeb 0 t\u1edbi 9\n\n       uniqueNums = &#91;...new Set(ranDom)]; \/\/ lo\u1ea1i tr\u00f9ng l\u1eb7p\n\n       i = uniqueNums.length; \/\/ \u0111\u1ebfm s\u1ed1 l\u01b0\u1ee3ng c\u1ee7a m\u1ea3ng b\u1ecf tr\u00f9ng\n   }\nreturn uniqueNums;\n\n}\n\ndocument.getElementById(\"demo\").innerHTML = random3();\n\n&lt;\/script&gt;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>B\u00e0i to\u00e1n 3: Cho m\u1ed9t danh m\u1ee5c g\u1ed3m 7 s\u1ea3n ph\u1ea9m, h\u00e3y vi\u1ebft h\u00e0m show ra ng\u1eabu nhi\u00ean 3 s\u1ea3n ph\u1ea9m (c\u0169ng kh\u00f4ng tr\u00f9ng nhau) trong 7 s\u1ea3n ph\u1ea9m \u0111\u00f3.<\/strong><\/p>\n\n\n\n<p>\u1ede tr\u00ean l\u00e0 s\u1ed1, b\u00e2y gi\u1edd gi\u00e1 s\u1eed ch\u00fang ta c\u00f3 m\u1ea3ng g\u1ed3m 7 s\u1ea3n ph\u1ea9m l\u00e0 Coca, Pepsi, Fanta, 7up, Redbull, N\u01b0\u1edbc kho\u00e1ng, Tr\u00e0. <\/p>\n\n\n\n<p>V\u1eady l\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 l\u1ea5y 3 s\u1ea3n ph\u1ea9m b\u1ea5t k\u1ef3 trong 7 s\u1ea3n ph\u1ea9m \u0111\u00f3.<\/p>\n\n\n\n<p>V\u00ec \u0111\u00e3 c\u00f3 b\u00e0i 2 d\u1eabn l\u1ed1i r\u1ed3i, ch\u00fang ta s\u1ebd ch\u1ec9 c\u1ea7n thay \u0111\u1ed5i m\u00e3 m\u1ed9t ch\u00fat:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n\n&lt;script&gt;\n\nconst product = &#91;\"Coca\", \"Pepsi\", \"Fanta\", \"7up\", \"Redbull\", \"N\u01b0\u1edbc kho\u00e1ng\", \"Tr\u00e0\"];\n\nfunction randon3p(product) {\n    let i = 0; \n    ranDom = &#91;]; \/\/ m\u1ea3ng ch\u1ee9a s\u1ea3n ph\u1ea9m ng\u1eabu nhi\u00ean\n    uniqueNums = &#91;]; \/\/ m\u1ea3ng lo\u1ea1i b\u1ecf tr\u00f9ng l\u1eb7p\n\n    while (i &lt; 3) {\n    k = Math.floor(Math.random() * 7); \/\/ l\u1ea5y gi\u00e1 tr\u1ecb ng\u1eabu nhi\u00ean\n    ranDom&#91;i] = product&#91;k]; \/\/ g\u00e1n s\u1ea3n ph\u1ea9m ng\u1eabu nhi\u00ean v\u00e0o m\u1ea3ng ranDom\n    uniqueNums = &#91;...new Set(ranDom)]; \/\/ lo\u1ea1i tr\u00f9ng\n    i = uniqueNums.length; \/\/ \u0111\u1ebfm s\u1ed1 l\u01b0\u1ee3ng m\u1ea3ng \u0111\u00e3 lo\u1ea1i tr\u00f9ng \u0111\u1ec3 l\u00e0m \u0111i\u1ec1u ki\u1ec7n cho while, kh\u00f4ng c\u00f3 c\u00e1i n\u00e0y v\u00f2ng l\u1eb7p s\u1ebd v\u00f4 t\u1eadn\n    }\nreturn uniqueNums;\n}\ndocument.getElementById(\"demo\").innerHTML = randon3p(product);\n\n&lt;\/script&gt;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>B\u00e0i to\u00e1n 4: Cho 7 s\u1ea3n ph\u1ea9m b\u1ea5t k\u1ef3 g\u1ed3m t\u00ean s\u1ea3n ph\u1ea9m v\u00e0 gi\u00e1, h\u00e3y vi\u1ebft h\u00e0m \u0111\u1ec3 l\u1ea5y ra (c\u00e1c) s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 cao nh\u1ea5t \u0111\u1ec3 hi\u1ec7n ra m\u00e0n h\u00ecnh<\/strong>.<\/p>\n\n\n\n<p>C\u1ea5u tr\u00fac c\u1ee7a m\u1ea3ng \u0111\u1ea7u v\u00e0o:<\/p>\n\n\n\n<p><code>product = [\"Coca 7\", \"Pepsi 12\", \"Fanta 10\", \"7up 9\", \"Redbull 12\", \"N\u01b0\u1edbc kho\u00e1ng 3\", \"Tr\u00e0 5\"];<\/code><\/p>\n\n\n\n<p>Trong \u0111\u00f3 t\u00ean \u0111\u1ee9ng tr\u01b0\u1edbc, gi\u00e1 \u0111\u1ee9ng sau. T\u00ean kh\u00f4ng b\u1ecb tr\u00f9ng nhau, gi\u00e1 c\u00f3 th\u1ec3 gi\u1ed1ng nhau. C\u1ea5u tr\u00fac \u0111\u00e3 \u0111\u01b0\u1ee3c chu\u1ea9n h\u00f3a (t\u1ee9c l\u00e0 kh\u00f4ng c\u00f3 chuy\u1ec7n thi\u1ebfu gi\u00e1, ho\u1eb7c gi\u00e1 kh\u00f4ng ph\u1ea3i s\u1ed1). \u00dd l\u00e0 ta t\u1eadp trung t\u1ea1o h\u00e0m th\u00f4i ch\u1ee9 kh\u00f4ng c\u1ea7n chu\u1ea9n h\u00f3a th\u00f4ng tin \u0111\u1ea7u v\u00e0o n\u1eefa.<\/p>\n\n\n\n<p>V\u1eady l\u00e0 gi\u00e1 l\u00fac n\u00e0o c\u0169ng \u0111\u1ee9ng cu\u1ed1i, ch\u00fang ta ch\u1ec9 vi\u1ec7c t\u00e1ch gi\u00e1 ra kh\u1ecfi s\u1ea3n ph\u1ea9m, \u0111\u01b0a n\u00f3 v\u00e0o m\u1ea3ng, r\u1ed3i t\u00ecm gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t, sau \u0111\u00f3 quay ra t\u00ecm xem s\u1ea3n ph\u1ea9m n\u00e0o c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t \u0111\u00f3 r\u1ed3i show ra l\u00e0 \u0111\u01b0\u1ee3c.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n\n&lt;script&gt;\nproducts = &#91;\"Coca 7\", \"Pepsi 12\", \"Fanta 10\", \"7up 9\", \"Redbull 12\", \"N\u01b0\u1edbc kho\u00e1ng 3\", \"Tr\u00e0 5\"];\n\nfunction maxPrice(products) {\n      const price = &#91;];\n\n      for (let i = 0; i &lt; products.length; i++) {\n            let ps = products&#91;i].split(\" \"); \/\/ m\u1ea3ng t\u00e1ch t\u00ean v\u00e0 gi\u00e1\n\n            let x = ps.length - 1; \/\/ l\u1ea5y v\u1ecb tr\u00ed c\u1ee7a gi\u00e1 trong m\u1ea3ng v\u1eeba t\u00e1ch\n\n            let pr = parseFloat(ps&#91;x]); \/\/ l\u1ea5y gi\u00e1 v\u00e0 chuy\u1ec3n th\u00e0nh gi\u00e1 tr\u1ecb s\u1ed1\n\n            price&#91;i] = pr; \/\/ \u0111\u01b0a gi\u00e1 s\u1ea3n ph\u1ea9m v\u00e0o m\u1ea3ng\n      }\n\n\n      let maxPrice = Math.max(...price); \/\/ t\u00ecm \u0111\u01b0\u1ee3c gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t trong m\u1ea3ng\n\n      const maxProducts = &#91;]; let v = 0;\n\n      for (let j = 0; j &lt; products.length; j++) {\n            let ps = products&#91;j].split(\" \"); \/\/ m\u1ea3ng t\u00e1ch t\u00ean v\u00e0 gi\u00e1\n\n            let x = ps.length - 1; \/\/ l\u1ea5y v\u1ecb tr\u00ed c\u1ee7a gi\u00e1 trong m\u1ea3ng v\u1eeba t\u00e1ch\n\n            let pr = parseFloat(ps&#91;x]); \/\/ l\u1ea5y gi\u00e1 v\u00e0 chuy\u1ec3n th\u00e0nh gi\u00e1 tr\u1ecb s\u1ed1\n\n            if (pr == maxPrice) {maxProducts&#91;v] = products&#91;j]; v++;} \/\/ \u0111\u01b0a s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 \u0111\u00fang v\u1edbi gi\u00e1 cao nh\u1ea5t t\u00ecm \u0111\u01b0\u1ee3c v\u00e0o m\u1ea3ng\n      }\nreturn maxProducts;      \n}\n\ndocument.getElementById(\"demo\").innerHTML = maxPrice(products); \/\/ show c\u00e1c s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 cao nh\u1ea5t ra kh\u1ecfi m\u00e0n h\u00ecnh\n\n&lt;\/script&gt;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<p><strong>B\u00e0i to\u00e1n 5: Cho 7 s\u1ea3n ph\u1ea9m b\u1ea5t k\u1ef3 g\u1ed3m t\u00ean s\u1ea3n ph\u1ea9m v\u00e0 gi\u00e1, h\u00e3y vi\u1ebft h\u00e0m \u0111\u1ec3 s\u1eafp x\u1ebfp c\u00e1c s\u1ea3n ph\u1ea9m \u0111\u00f3 theo gi\u00e1 gi\u1ea3m d\u1ea7n<\/strong><\/p>\n\n\n\n<p>C\u1ea5u tr\u00fac m\u1ea3ng \u0111\u1ea7u v\u00e0o nh\u01b0 \u1edf b\u00e0i 4.<\/p>\n\n\n\n<p>Ch\u00fang ta s\u1ebd d\u00f9ng h\u00e0m \u1edf b\u00e0i 4 \u0111\u1ec3 x\u1eed l\u00fd c\u00e1i n\u00e0y. \u0110\u1ea7u ti\u00ean t\u00ecm s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t trong m\u1ea3ng ban \u0111\u1ea7u.<\/p>\n\n\n\n<p>Ti\u1ebfp \u0111\u00f3 lo\u1ea1i b\u1ecf s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t \u0111\u00f3 trong m\u1ea3ng \u0111\u1ea7u, r\u1ed3i l\u1ea1i quay ra t\u00ecm s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t trong m\u1ea3ng c\u00e1c s\u1ea3n ph\u1ea9m c\u00f2n l\u1ea1i.<\/p>\n\n\n\n<p>C\u1ee9 th\u1ebf cho \u0111\u1ebfn khi h\u1ebft.<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>&lt;p id=\"demo\"&gt;&lt;\/p&gt;\n\n&lt;script&gt;\nconst products = &#91;\"Coca 7\", \"Pepsi 2\", \"Fanta 10\", \"Seven Up 9\", \"Redbull 15\", \"N\u01b0\u1edbc kho\u00e1ng 9\", \"Tr\u00e0 3\"];\n\nlet count = products.length; \/\/ l\u1ea5y s\u1ed1 l\u01b0\u1ee3ng c\u1ee7a m\u1ea3ng\n\nfunction maxPriceRemove(products) {\n     const price = &#91;]; \/\/ t\u1ea1o m\u1ea3ng gi\u00e1\n     for (let i = 0; i &lt; products.length; i++) {\n                let ps = products&#91;i].split(\" \"); \/\/ m\u1ea3ng t\u00e1ch t\u00ean v\u00e0 gi\u00e1\n\n                let x = ps.length - 1; \/\/ l\u1ea5y v\u1ecb tr\u00ed c\u1ee7a gi\u00e1 trong m\u1ea3ng v\u1eeba t\u00e1ch\n\n                let pr = parseFloat(ps&#91;x]); \/\/ l\u1ea5y gi\u00e1 v\u00e0 chuy\u1ec3n th\u00e0nh gi\u00e1 tr\u1ecb s\u1ed1\n\n                price&#91;i] = pr; \/\/ \u0111\u01b0a gi\u00e1 s\u1ea3n ph\u1ea9m v\u00e0o m\u1ea3ng\n      }\n\n      let maxPrice = Math.max(...price); \/\/ t\u00ecm \u0111\u01b0\u1ee3c gi\u00e1 tr\u1ecb l\u1edbn nh\u1ea5t trong m\u1ea3ng\n\n      let maxProducts; let v;\n\n      for (let j = 0; j &lt; products.length; j++) {\n                let ps = products&#91;j].split(\" \"); \/\/ m\u1ea3ng t\u00e1ch t\u00ean v\u00e0 gi\u00e1\n                \n                let x = ps.length - 1; \/\/ l\u1ea5y v\u1ecb tr\u00ed c\u1ee7a gi\u00e1 trong m\u1ea3ng v\u1eeba t\u00e1ch\n                \n                let pr = parseFloat(ps&#91;x]); \/\/ l\u1ea5y gi\u00e1 v\u00e0 chuy\u1ec3n th\u00e0nh gi\u00e1 tr\u1ecb s\u1ed1\n                \n                if (pr === maxPrice) { \/\/ so s\u00e1nh\n                    \n                maxProducts = products&#91;j]; \/\/ l\u1ea5y \u0111\u01b0\u1ee3c s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 cao nh\u1ea5t\n                \n                v = j; break} \/\/ t\u00ecm \u0111\u01b0\u1ee3c v\u1ecb tr\u00ed c\u1ee7a s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 cao nh\u1ea5t trong m\u1ea3ng, t\u00ecm \u0111c th\u00ec b\u1ebb v\u00f2ng l\u1eb7p lu\u00f4n\n       }\n\n       products.splice(v,1); \/\/lo\u1ea1i b\u1ecf s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t c\u1ee7a product \u0111\u1ec3 v\u00f2ng l\u1eb7p sau s\u1ebd t\u00ecm \u0111\u01b0\u1ee3c s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 l\u1edbn th\u1ee9 nh\u00ec\n \nreturn maxProducts; \/\/ tr\u1ea3 k\u1ebft qu\u1ea3 v\u1ec1 h\u00e0m\n}\n\nconst rankProducts = &#91;]; \/\/ t\u1ea1o m\u1ea3ng s\u1ea3n ph\u1ea9m \u0111\u00e3 s\u1eafp x\u1ebfp\n\nfor (let i = 0; i &lt; count; i++) {\n\t rs = maxPriceRemove(products); \/\/ l\u1ea5y s\u1ea3n ph\u1ea7m c\u00f3 gi\u00e1 l\u1edbn nh\u1ea5t\n         rankProducts&#91;i] = rs; \/\/ \u0111\u01b0a n\u00f3 v\u00e0o m\u1ea3ng\n}\n\ndocument.getElementById(\"demo\").innerHTML = rankProducts; \/\/ show c\u00e1c s\u1ea3n ph\u1ea9m c\u00f3 gi\u00e1 t\u1eeb cao \u0111\u1ebfn th\u1ea5p ra m\u00e0n h\u00ecnh\n\n&lt;\/script&gt; <\/code><\/pre>\n\n\n\n<p>H\u1eb9n g\u1eb7p l\u1ea1i c\u00e1c b\u1ea1n trong c\u00e1c b\u00e0i vi\u1ebft kh\u00e1c.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>H\u00f4m nay ch\u00fang ta s\u1ebd th\u1ef1c h\u00e0nh vi\u1ebft c\u00e1c h\u00e0m JS \u0111\u01a1n gi\u1ea3n, qua \u0111\u00f3 s\u1ebd c\u1ea3i thi\u1ec7n d\u1ea7n kh\u1ea3 n\u0103ng t\u1ea1o c\u00e1c h\u00e0m ph\u1ee9c t\u1ea1p h\u01a1n. B\u00e0i to\u00e1n 1: nh\u1eadp v\u00e0o ba s\u1ed1 ch\u1ec9 \u0111\u1ed9 d\u00e0i, h\u00e3y xem n\u00f3 c\u00f3 ph\u1ea3i l\u00e0 ba \u0111\u1ed9 d\u00e0i c\u1ee7a m\u1ed9t c\u1ea1nh tam gi\u00e1c kh\u00f4ng? C\u00e1ch gi\u1ea3i: ba &hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[236],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.6 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Th\u1ef1c h\u00e0nh vi\u1ebft h\u00e0m trong JavaScript &#8226; Ki\u1ebfn c\u00e0ng<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/kiencang.net\/thuc-hanh-viet-ham-trong-javascript\/\" \/>\n<meta property=\"og:locale\" content=\"vi_VN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Th\u1ef1c h\u00e0nh vi\u1ebft h\u00e0m trong JavaScript &#8226; Ki\u1ebfn c\u00e0ng\" \/>\n<meta property=\"og:description\" content=\"H\u00f4m nay ch\u00fang ta s\u1ebd th\u1ef1c h\u00e0nh vi\u1ebft c\u00e1c h\u00e0m JS \u0111\u01a1n gi\u1ea3n, qua \u0111\u00f3 s\u1ebd c\u1ea3i thi\u1ec7n d\u1ea7n kh\u1ea3 n\u0103ng t\u1ea1o c\u00e1c h\u00e0m ph\u1ee9c t\u1ea1p h\u01a1n. 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