{"id":3229,"date":"2016-07-11T03:24:23","date_gmt":"2016-07-11T03:24:23","guid":{"rendered":"https:\/\/kiencang.net\/?p=3229"},"modified":"2016-07-11T03:24:23","modified_gmt":"2016-07-11T03:24:23","slug":"cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript","status":"publish","type":"post","link":"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/","title":{"rendered":"C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn x\u1eed l\u00fd s\u1ed1 trong JavaScript"},"content":{"rendered":"\n<p>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 gi\u00fap b\u1ea1n d\u1ec5 d\u00e0ng x\u1eed l\u00fd c\u00e1c con s\u1ed1 h\u01a1n.<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_60 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title \" >M\u1ee5c l\u1ee5c<\/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\" role=\"button\"><label for=\"item-6577d6b48a146\" ><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><\/label><input aria-label=\"Toggle\" aria-label=\"item-6577d6b48a146\"  type=\"checkbox\" id=\"item-6577d6b48a146\"><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Cac_thuoc_tinh_va_phuong_thuc_lien_quan_den_so\" title=\"C\u00e1c thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1\">C\u00e1c thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_toString\" title=\"Ph\u01b0\u01a1ng th\u1ee9c toString()\">Ph\u01b0\u01a1ng th\u1ee9c toString()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_toExponential\" title=\"Ph\u01b0\u01a1ng th\u1ee9c toExponential()\">Ph\u01b0\u01a1ng th\u1ee9c toExponential()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_toFixed\" title=\"Ph\u01b0\u01a1ng th\u1ee9c toFixed()\">Ph\u01b0\u01a1ng th\u1ee9c toFixed()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_toPrecision\" title=\"Ph\u01b0\u01a1ng th\u1ee9c toPrecision()\">Ph\u01b0\u01a1ng th\u1ee9c toPrecision()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_valueOf\" title=\"Ph\u01b0\u01a1ng th\u1ee9c valueOf()\">Ph\u01b0\u01a1ng th\u1ee9c valueOf()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Chuyen_bien_thanh_dang_so\" title=\"Chuy\u1ec3n bi\u1ebfn th\u00e0nh d\u1ea1ng s\u1ed1\">Chuy\u1ec3n bi\u1ebfn th\u00e0nh d\u1ea1ng s\u1ed1<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Cac_phuong_thuc_toan_cuc\" title=\"C\u00e1c ph\u01b0\u01a1ng th\u1ee9c to\u00e0n c\u1ee5c\">C\u00e1c ph\u01b0\u01a1ng th\u1ee9c to\u00e0n c\u1ee5c<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_Number\" title=\"Ph\u01b0\u01a1ng th\u1ee9c Number()\">Ph\u01b0\u01a1ng th\u1ee9c Number()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_parseInt\" title=\"Ph\u01b0\u01a1ng th\u1ee9c parseInt()\">Ph\u01b0\u01a1ng th\u1ee9c parseInt()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Phuong_thuc_parseFloat\" title=\"Ph\u01b0\u01a1ng th\u1ee9c parseFloat()\">Ph\u01b0\u01a1ng th\u1ee9c parseFloat()<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/kiencang.net\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/#Cac_thuoc_tinh_lien_quan_den_so\" title=\"C\u00e1c thu\u1ed9c t\u00ednh li\u00ean quan \u0111\u1ebfn s\u1ed1\">C\u00e1c thu\u1ed9c t\u00ednh li\u00ean quan \u0111\u1ebfn s\u1ed1<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Cac_thuoc_tinh_va_phuong_thuc_lien_quan_den_so\"><\/span>C\u00e1c thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>C\u00e1c gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7 (nh\u01b0 3,14159 ho\u1eb7c 2016) kh\u00f4ng c\u00f3 thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c b\u1edfi v\u00ec n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u1ed1i t\u01b0\u1ee3ng.<\/p>\n\n\n\n<p>Nh\u01b0ng v\u1edbi JavaScript, c\u00e1c ph\u01b0\u01a1ng th\u1ee9c v\u00e0 thu\u1ed9c t\u00ednh \u0111\u01b0\u1ee3c cung c\u1ea5p cho c\u00e1c gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7, b\u1edfi v\u00ec JavaScript x\u1eed l\u00fd c\u00e1c gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7 nh\u01b0 \u0111\u1ed1i t\u01b0\u1ee3ng khi th\u1ef1c thi ph\u01b0\u01a1ng th\u1ee9c v\u00e0 \u0111\u1ed1i t\u01b0\u1ee3ng.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_toString\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c toString()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>toString()<\/strong>&nbsp;tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1 nh\u01b0 l\u00e0 m\u1ed9t chu\u1ed7i.<\/p>\n\n\n\n<p>T\u1ea5t c\u1ea3 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng cho b\u1ea5t c\u1ee9 ki\u1ec3u s\u1ed1 n\u00e0o (s\u1ed1 thu\u1ea7n tu\u00fd, c\u00e1c bi\u1ebfn ho\u1eb7c c\u00e1c bi\u1ec3u th\u1ee9c):<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 123;\nx.toString();            \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb bi\u1ebfn x\n(123).toString();        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb s\u1ed1 thu\u1ea7n tu\u00fd 123\n(100 + 23).toString();   \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb bi\u1ec3u th\u1ee9c 100 + 23<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_toExponential\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c toExponential()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>toExponential()<\/strong>&nbsp;tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 l\u00e0 m\u1ed9t chu\u1ed7i, v\u1edbi m\u1ed9t s\u1ed1 \u0111\u01b0\u1ee3c l\u00e0m tr\u00f2n v\u00e0 \u0111\u01b0\u1ee3c vi\u1ebft d\u01b0\u1edbi d\u1ea1ng s\u1eed d\u1ee5ng s\u1ed1 m\u0169.<\/p>\n\n\n\n<p>M\u1ed9t \u0111\u1ed1i s\u1ed1 \u0111\u1ecbnh ngh\u0129a s\u1ed1 k\u00fd t\u1ef1 \u0111\u1eb1ng sau d\u1ea5u ch\u1ea5m th\u1eadp ph\u00e2n:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u0110\u1ecbnh ngh\u0129a<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 9.656;\nx.toExponential(2);     \/\/ tr\u1ea3 v\u1ec1 9.66e+0\nx.toExponential(4);     \/\/ tr\u1ea3 v\u1ec1 9.6560e+0\nx.toExponential(6);     \/\/ tr\u1ea3 v\u1ec1 9.656000e+0<\/code><\/pre>\n\n\n\n<p>\u0110\u1ed1i s\u1ed1 l\u00e0 tu\u1ef3 ch\u1ecdn. N\u1ebfu b\u1ea1n kh\u00f4ng ch\u1ec9 \u0111\u1ecbnh n\u00f3, JavaScript s\u1ebd kh\u00f4ng l\u00e0m tr\u00f2n s\u1ed1.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_toFixed\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c toFixed()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>toFixed()<\/strong>&nbsp;tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 l\u00e0 m\u1ed9t chu\u1ed7i, n\u00f3 r\u1ea5t gi\u1ed1ng v\u1edbi ph\u00e9p l\u00e0m tr\u00f2n, ch\u1ec9 \u0111\u1ecbnh m\u1ed9t s\u1ed1 c\u1ee5 th\u1ec3 sau d\u1ea5u ch\u1ea5m th\u1eadp ph\u00e2n:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 9.656;\nx.toFixed(0);           \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 10\nx.toFixed(2);           \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 9.66\nx.toFixed(4);           \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 9.6560\nx.toFixed(6);           \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 9.656000<\/code><\/pre>\n\n\n\n<p>toFixed(2) r\u1ea5t ho\u00e0n h\u1ea3o \u0111\u1ec3 l\u00e0m vi\u1ec7c v\u1edbi ti\u1ec1n t\u1ec7.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_toPrecision\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c toPrecision()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>toPrecision()<\/strong>&nbsp;tr\u1ea3 v\u1ec1 m\u1ed9t chu\u1ed7i, c\u0169ng kh\u00e1 gi\u1ed1ng v\u1edbi ph\u00e9p l\u00e0m tr\u00f2n nh\u01b0ng l\u1ea7n n\u00e0y l\u00e0 ch\u1ec9 \u0111\u1ecbnh \u0111\u1ed9 d\u00e0i c\u1ee7a chu\u1ed7i:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 9.656;\nx.toPrecision();        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 9.656\nx.toPrecision(2);       \/\/ tr\u1ea3 v\u1ec1 9.7\nx.toPrecision(4);       \/\/ tr\u1ea3 v\u1ec1 9.656\nx.toPrecision(6);       \/\/ tr\u1ea3 v\u1ec1 9.65600<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_valueOf\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c valueOf()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>valueOf()<\/strong>&nbsp;tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1 nh\u01b0 l\u00e0 m\u1ed9t s\u1ed1 (nghe l\u1ed9n ru\u1ed9t nh\u1ec9, nh\u01b0ng c\u00e1c b\u1ea1n s\u1ebd hi\u1ec3u ngay th\u00f4i).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 123;\nx.valueOf();            \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb bi\u1ebfn x\n(123).valueOf();        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb s\u1ed1 thu\u1ea7n tu\u00fd 123\n(100 + 23).valueOf();   \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 123 t\u1eeb bi\u1ec3u th\u1ee9c 100 + 23<\/code><\/pre>\n\n\n\n<p>Trong JavaScript, m\u1ed9t s\u1ed1 c\u00f3 th\u1ec3 l\u00e0 gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7 (typeof = number) ho\u1eb7c m\u1ed9t \u0111\u1ed1i t\u01b0\u1ee3ng (typeof = object).<\/p>\n\n\n\n<p>Ph\u01b0\u01a1ng th\u1ee9c valueOf() \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng n\u1ed9i b\u1ed9 trong JavaScript \u0111\u1ec3 chuy\u1ec3n \u0111\u1ed1i t\u01b0\u1ee3ng s\u1ed1 th\u00e0nh gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7.<\/p>\n\n\n\n<p>Kh\u00f4ng c\u00f3 l\u00fd do \u0111\u1ec3 s\u1eed d\u1ee5ng n\u00f3 trong m\u00e3 c\u1ee7a b\u1ea1n.<\/p>\n\n\n\n<p>\u0110\u1ecbnh d\u1ea1ng d\u1eef li\u1ec7u trong JavaScript c\u00f3 hai ph\u01b0\u01a1ng th\u1ee9c l\u00e0 valueOf() v\u00e0 toString().<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Chuyen_bien_thanh_dang_so\"><\/span>Chuy\u1ec3n bi\u1ebfn th\u00e0nh d\u1ea1ng s\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>C\u00f3 3 ph\u01b0\u01a1ng th\u1ee9c c\u1ee7a JavaScript c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng \u0111\u1ec3 chuy\u1ec3n \u0111\u1ed5i bi\u1ebfn th\u00e0nh m\u1ed9t s\u1ed1:<\/p>\n\n\n\n<ul><li>Ph\u01b0\u01a1ng th\u1ee9c Number()<\/li><li>Ph\u01b0\u01a1ng th\u1ee9c parseInt()<\/li><li>Ph\u01b0\u01a1ng th\u1ee9c parseFloat()<\/li><\/ul>\n\n\n\n<p>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c n\u00e0y kh\u00f4ng ph\u1ea3i l\u00e0 ph\u01b0\u01a1ng th\u1ee9c c\u1ee7a s\u1ed1, nh\u01b0ng n\u00f3 l\u00e0 c\u00e1c ph\u01b0\u01a1ng th\u1ee9c to\u00e0n c\u1ee5c.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Cac_phuong_thuc_toan_cuc\"><\/span>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c to\u00e0n c\u1ee5c<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c to\u00e0n c\u1ee5c trong JavaScript c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng tr\u00ean t\u1ea5t c\u1ea3 c\u00e1c d\u1ea1ng d\u1eef li\u1ec7u c\u1ee7a JavaScript.<\/p>\n\n\n\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan nh\u1ea5t khi l\u00e0m vi\u1ec7c v\u1edbi c\u00e1c con s\u1ed1:<\/p>\n\n\n\n<figure class=\"wp-block-table w3-table-all notranslate\"><table><tbody><tr><th>Ph\u01b0\u01a1ng th\u1ee9c<\/th><th>M\u00f4 t\u1ea3<\/th><\/tr><tr><td>Number()<\/td><td>Tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1, chuy\u1ec3n \u0111\u1ed5i t\u1eeb \u0111\u1ed1i s\u1ed1 c\u1ee7a n\u00f3.<\/td><\/tr><tr><td>parseFloat()<\/td><td>Ph\u00e2n t\u00edch \u0111\u1ed1i s\u1ed1 v\u00e0 tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1 th\u1ef1c<\/td><\/tr><tr><td>parseInt()<\/td><td>Ph\u00e2n t\u00edch \u0111\u1ed1i s\u1ed1 v\u00e0 tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1 nguy\u00ean<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_Number\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c Number()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>Number()<\/strong>&nbsp;c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 chuy\u1ec3n \u0111\u1ed5i bi\u1ebfn trong JavaScript th\u00e0nh c\u00e1c con s\u1ed1:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>x = true;\nNumber(x);        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 1<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>x = false;\nNumber(x);        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 0<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>x = new Date();\nNumber(x);        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 1404568027739<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>x = \"10\"\nNumber(x);        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 10<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>x = \"10 20\"\nNumber(x);        \/\/ tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 NaN<\/code><\/pre>\n\n\n\n<p>Khi s\u1eed d\u1ee5ng Date(), ph\u01b0\u01a1ng th\u1ee9c Number() tr\u1ea3 v\u1ec1 con s\u1ed1 t\u00ednh theo mili gi\u00e2y k\u1ec3 t\u1eeb ng\u00e0y 1.1.1970<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_parseInt\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c parseInt()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>parseInt()<\/strong>&nbsp;ph\u00e2n t\u00edch m\u1ed9t chu\u1ed7i v\u00e0 tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1 nguy\u00ean. Kho\u1ea3ng tr\u1ed1ng \u0111\u01b0\u1ee3c ph\u00e9p. Ch\u1ec9 s\u1ed1 \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c tr\u1ea3 v\u1ec1:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>parseInt(\"10\");         \/\/ tr\u1ea3 v\u1ec1 10\nparseInt(\"10.33\");      \/\/ tr\u1ea3 v\u1ec1 10\nparseInt(\"10 20 30\");   \/\/ tr\u1ea3 v\u1ec1 10\nparseInt(\"10 years\");   \/\/ tr\u1ea3 v\u1ec1 10\nparseInt(\"cu\u1ed1i n\u0103m l\u1edbp 10\");   \/\/ tr\u1ea3 v\u1ec1 NaN<\/code><\/pre>\n\n\n\n<p>N\u1ebfu m\u1ed9t s\u1ed1 kh\u00f4ng th\u1ec3 chuy\u1ec3n \u0111\u1ed5i, NaN (Kh\u00f4ng ph\u1ea3i l\u00e0 s\u1ed1 &nbsp;&#8211; Not a Number) s\u1ebd \u0111\u01b0\u1ee3c tr\u1ea3 v\u1ec1.<\/p>\n\n\n\n<hr class=\"wp-block-separator\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Phuong_thuc_parseFloat\"><\/span>Ph\u01b0\u01a1ng th\u1ee9c parseFloat()<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p><strong>parseFloat()<\/strong>&nbsp;ph\u00e2n t\u00edch m\u1ed9t chu\u1ed7i v\u00e0 tr\u1ea3 v\u1ec1 m\u1ed9t s\u1ed1. Kho\u1ea3ng tr\u1ed1ng l\u00e0 cho ph\u00e9p. Ch\u1ec9 s\u1ed1 \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c tr\u1ea3 v\u1ec1.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Vsi d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>parseFloat(\"10\");        \/\/ tr\u1ea3 v\u1ec1 10\nparseFloat(\"10.33\");     \/\/ tr\u1ea3 v\u1ec1 10.33\nparseFloat(\"10 20 30\");  \/\/ tr\u1ea3 v\u1ec1 10\nparseFloat(\"10 years\");  \/\/ tr\u1ea3 v\u1ec1 10\nparseFloat(\"cu\u1ed1i n\u0103m l\u1edbp 10\");  \/\/ tr\u1ea3 v\u1ec1 NaN<\/code><\/pre>\n\n\n\n<p>N\u1ebfu s\u1ed1 kh\u00f4ng th\u1ec3 chuy\u1ec3n \u0111\u1ed5i, NaN s\u1ebd \u0111\u01b0\u1ee3c tr\u1ea3 v\u1ec1.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Cac_thuoc_tinh_lien_quan_den_so\"><\/span>C\u00e1c thu\u1ed9c t\u00ednh li\u00ean quan \u0111\u1ebfn s\u1ed1<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table w3-table-all notranslate\"><table><tbody><tr><th>Thu\u1ed9c t\u00ednh<\/th><th>M\u00f4 t\u1ea3<\/th><\/tr><tr><td>MAX_VALUE<\/td><td>Tr\u1ea3 v\u1ec1 s\u1ed1 l\u1edbn nh\u1ea5t c\u00f3 th\u1ec3 trong JavaScript<\/td><\/tr><tr><td>MIN_VALUE<\/td><td>Tr\u1ea3 v\u1ec1 s\u1ed1 nh\u1ecf nh\u1ea5t c\u00f3 th\u1ec3 trong JavaScript<\/td><\/tr><tr><td>NEGATIVE_INFINITY<\/td><td>\u0110\u1ea1i di\u1ec7n cho \u00e2m v\u00f4 c\u1ef1c<\/td><\/tr><tr><td>NaN<\/td><td>\u0110\u1ea1i di\u1ec7n cho gi\u00e1 tr\u1ecb &#8220;Kh\u00f4ng-ph\u1ea3i-l\u00e0-s\u1ed1&#8221;<\/td><\/tr><tr><td>POSITIVE_INFINITY<\/td><td>\u0110\u1ea1i di\u1ec7n cho d\u01b0\u01a1ng v\u00f4 c\u1ef1c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = Number.MAX_VALUE;<\/code><\/pre>\n\n\n\n<p>C\u00e1c thu\u1ed9c t\u00ednh s\u1ed1 thu\u1ed9c v\u1ec1 \u0111\u1ed1i t\u01b0\u1ee3ng s\u1ed1 c\u1ee7a JavaScript g\u1ecdi l\u00e0 S\u1ed1.<\/p>\n\n\n\n<p>C\u00e1c thu\u1ed9c t\u00ednh n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c truy c\u1eadp nh\u01b0 <strong>Number<\/strong>.MAX_VALUE.<\/p>\n\n\n\n<p>S\u1eed d\u1ee5ng myNumber.MAX_VALUE, m\u00e0 myNumber l\u00e0 m\u1ed9t bi\u1ebfn, bi\u1ec3u th\u1ee9c ho\u1eb7c gi\u00e1 tr\u1ecb, s\u1ebd tr\u1ea3 v\u1ec1 k\u1ebft qu\u1ea3 kh\u00f4ng \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">V\u00ed d\u1ee5<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>var x = 6;\nvar y = x.MAX_VALUE; \/\/ y tr\u1edf th\u00e0nh undefined (kh\u00f4ng \u0111\u1ecbnh ngh\u0129a)<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 gi\u00fap b\u1ea1n d\u1ec5 d\u00e0ng x\u1eed l\u00fd c\u00e1c con s\u1ed1 h\u01a1n. C\u00e1c thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 C\u00e1c gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7 (nh\u01b0 3,14159 ho\u1eb7c 2016) kh\u00f4ng c\u00f3 thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c b\u1edfi v\u00ec n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u1ed1i t\u01b0\u1ee3ng. Nh\u01b0ng v\u1edbi JavaScript, c\u00e1c &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>C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn x\u1eed l\u00fd s\u1ed1 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\/cac-phuong-thuc-lien-quan-den-xu-ly-so-trong-javascript\/\" \/>\n<meta property=\"og:locale\" content=\"vi_VN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn x\u1eed l\u00fd s\u1ed1 trong JavaScript &#8226; Ki\u1ebfn c\u00e0ng\" \/>\n<meta property=\"og:description\" content=\"C\u00e1c ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 gi\u00fap b\u1ea1n d\u1ec5 d\u00e0ng x\u1eed l\u00fd c\u00e1c con s\u1ed1 h\u01a1n. C\u00e1c thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c li\u00ean quan \u0111\u1ebfn s\u1ed1 C\u00e1c gi\u00e1 tr\u1ecb nguy\u00ean thu\u1ef7 (nh\u01b0 3,14159 ho\u1eb7c 2016) kh\u00f4ng c\u00f3 thu\u1ed9c t\u00ednh v\u00e0 ph\u01b0\u01a1ng th\u1ee9c b\u1edfi v\u00ec n\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 \u0111\u1ed1i t\u01b0\u1ee3ng. 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