{"id":130045,"date":"2022-04-13T16:41:03","date_gmt":"2022-04-13T20:41:03","guid":{"rendered":"https:\/\/brainstation.io\/?post_type=codex-reference&#038;p=130045"},"modified":"2025-02-04T14:56:18","modified_gmt":"2025-02-04T19:56:18","slug":"array","status":"publish","type":"codex-reference","link":"https:\/\/brainstation.io\/learn\/javascript\/array","title":{"rendered":"Array"},"content":{"rendered":"\n<header class=\"wp-block-bstn-blocks-hero-with-overview bstn-blocks-hero-with-overview\"><div class=\"bstn-blocks-hero-with-overview__full-width-wrapper bstn-blocks-hero-with-overview__full-width-wrapper--main\"><svg fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-hero-with-overview__bg-flair--full\"><g opacity=\"0.35\"><path d=\"M-103.887 96.613H499.5\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path cliprule=\"evenodd\" d=\"M174.55-136.427v254.863-254.863zm139.219 0v254.863-254.863zm139.219 0v254.863-254.863zM35.332-232v350.436V-232z\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path fillrule=\"evenodd\" cliprule=\"evenodd\" d=\"M35.361 100.134c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.169 0c1.761 0 3.187-1.446 3.187-3.23 0-1.783-1.426-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23z\" fill=\"#3C4556\"><\/path><path d=\"M-244.061 214.487H499.5\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path cliprule=\"evenodd\" d=\"M174.55 214.009v254.863-254.863zm139.219 0v254.863-254.863zm139.219 0v254.863-254.863zM35.332 118.436v350.436-350.436z\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path fillrule=\"evenodd\" cliprule=\"evenodd\" d=\"M35.361 218.03c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23zm139.169 0c1.761 0 3.187-1.446 3.187-3.23 0-1.783-1.426-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23z\" fill=\"#3C4556\"><\/path><path d=\"M534.544 96.613h140.811m138.263 0H1417\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path cliprule=\"evenodd\" d=\"M674.718 96.772v21.664-21.664zM813.618-232v350.436V-232zm139.218 0v350.436V-232z\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path fillrule=\"evenodd\" cliprule=\"evenodd\" d=\"M535.357 100.134c1.761 0 3.187-1.446 3.187-3.23 0-1.783-1.426-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.169 0c1.761 0 3.187-1.446 3.187-3.23 0-1.783-1.426-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.23-3.187-3.23-1.76 0-3.187 1.447-3.187 3.23 0 1.784 1.427 3.23 3.187 3.23z\" fill=\"#3C4556\"><\/path><path d=\"M673.444 214.487H1417\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path cliprule=\"evenodd\" d=\"M674.718 118.436v228.739-228.739zm138.9 0v350.436-350.436zm139.218 0v350.436-350.436z\" stroke=\"#3C4556\" strokelinecap=\"square\"><\/path><path fillrule=\"evenodd\" cliprule=\"evenodd\" d=\"M813.696 218.03c1.761 0 3.187-1.446 3.187-3.23 0-1.783-1.426-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23zm139.17 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23zm-278.339 0c1.76 0 3.187-1.446 3.187-3.23 0-1.783-1.427-3.229-3.187-3.229-1.76 0-3.187 1.446-3.187 3.229 0 1.784 1.427 3.23 3.187 3.23z\" fill=\"#3C4556\"><\/path><\/g><\/svg><div class=\"bstn-blocks-hero-with-overview__container\"><div class=\"bstn-blocks-hero-with-overview__copy-container\"><p class=\"bstn-blocks-hero-with-overview__subtitle\">javascript Tutorial<\/p><h1 class=\"bstn-blocks-hero-with-overview__title\">JavaScript Array<\/h1><p class=\"bstn-blocks-hero-with-overview__description\"><meta charset=\"utf-8\">Learn more about one of the world&#8217;s most popular programming languages. <\/p><\/div><div class=\"bstn-blocks-hero-with-overview__image-container\"><img decoding=\"async\" class=\"bstn-blocks-hero-with-overview__image\" src=\"https:\/\/d3ghupt9z9s6o0.cloudfront.net\/app\/uploads\/2022\/04\/12115008\/Javascript-Light-Transparent.svg\" alt=\"\"\/><\/div><\/div><\/div><div class=\"bstn-blocks-hero-with-overview__full-width-wrapper bstn-blocks-hero-with-overview__full-width-wrapper--offset\"><div class=\"bstn-blocks-hero-with-overview__container\"><div class=\"bstn-blocks-hero-with-overview__card-container\"><div class=\"bstn-blocks-hero-with-overview__copy-card\"><nav class=\"bstn-blocks-hero-overview\"><h2 class=\"bstn-blocks-hero-overview__title\">Tutorial Contents<\/h2><ol class=\"bstn-blocks-hero-overview__list\">\n<li class=\"wp-block-bstn-blocks-overview-link bstn-blocks-hero-overview-link bstn-blocks-hero-overview-link--indent-0\" style=\"margin-left:0px\"><a class=\"bstn-blocks-hero-overview-link__anchor\" href=\"#javascript-array-methods\">JavaScript Array Methods<\/a><\/li>\n\n\n\n<li class=\"wp-block-bstn-blocks-overview-link bstn-blocks-hero-overview-link bstn-blocks-hero-overview-link--indent-0\" style=\"margin-left:0px\"><a class=\"bstn-blocks-hero-overview-link__anchor\" href=\"#array-push-or-add-array-elements\">Array Push or Add Array Elements<\/a><\/li>\n\n\n\n<li class=\"wp-block-bstn-blocks-overview-link bstn-blocks-hero-overview-link bstn-blocks-hero-overview-link--indent-0\" style=\"margin-left:0px\"><a class=\"bstn-blocks-hero-overview-link__anchor\" href=\"#array-pop-or-remove-elements-to-an-array\">Array Pop or Remove Elements from an Array<\/a><\/li>\n\n\n\n<li class=\"wp-block-bstn-blocks-overview-link bstn-blocks-hero-overview-link bstn-blocks-hero-overview-link--indent-0\" style=\"margin-left:0px\"><a class=\"bstn-blocks-hero-overview-link__anchor\" href=\"#javascript-array-includes\">JavaScript Array Includes<\/a><\/li>\n<\/ol><\/nav><\/div><\/div><\/div><\/div><\/header>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-1 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:66.66%\">\n<p class=\"is-style-bstn-paragraph-documentation-body\">JavaScript arrays are collections of items. These items can be of the same type or different but arrays provide a way to group them together into a common collection. Since a JavaScript array is a collection, it is stored and used differently than other primitive data types in JavaScript. Array values are indexed which means in order to obtain any value from this collection, a developer should use its index (starts at 0) within the collection itself. Let\u2019s see a visual representation of an array.<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table><tbody><tr><td><strong>Element<\/strong><\/td><td>10<\/td><td>20<\/td><td>30<\/td><td>40<\/td><td>50<\/td><td>60<\/td><td>70<\/td><td>80<\/td><td>90<\/td><td>100<\/td><\/tr><tr><td><strong>Position<\/strong><\/td><td>1<\/td><td>2<\/td><td>3<\/td><td>4<\/td><td>5<\/td><td>6<\/td><td>7<\/td><td>8<\/td><td>9<\/td><td>10<\/td><\/tr><tr><td><strong>Index<\/strong><\/td><td>0<\/td><td>1<\/td><td>2<\/td><td>3<\/td><td>4<\/td><td>5<\/td><td>6<\/td><td>7<\/td><td>8<\/td><td>9<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">In the example above, as you can see there are 10 numbers in the array. The length of the array is 10 however in order to extract any value for e.g. 60, a developer has to use the index value for that element which is 5 considering the index value starts at 0.<\/p>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">The easiest way to create an array in JavaScript is by using square brackets\u00a0<code>[]<\/code>, which is called an array literal notation. JavaScript also has a built-in array constructor\u00a0<code>new Array()<\/code>, but you can use\u00a0<code>[]<\/code>. Both statements will create an empty array.<\/p>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">Let\u2019s take a look at an example. As seen below, the&nbsp;<code>length<\/code>&nbsp;of the array can be figured out by using the&nbsp;<code>length<\/code>&nbsp;property on the array itself. In order to access a particular element from the array, use it\u2019s index value inside of the square brackets. An item can be changed in an array by reassigning it a new value using the equal sign&nbsp;<code>=<\/code>.<\/p>\n\n\n\n<div class=\"wp-block-bstn-blocks-code-snippet bstn-blocks-code-snippet\" data-code-snippet=\"true\"><div class=\"bstn-blocks-code-snippet__title-bar\"><span class=\"bstn-blocks-code-snippet__title\">Code Example<\/span><button class=\"bstn-blocks-code-snippet__copy-trigger\" aria-label=\"Copy code to clipboard\" data-copy-to-clipboard=\"true\"><svg viewbox=\"0 0 12 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-code-snippet__copy-trigger-icon\"><path d=\"M10.875.5h-7.5c-.633 0-1.125.516-1.125 1.125V2.75H1.125C.492 2.75 0 3.266 0 3.875v7.5A1.11 1.11 0 001.125 12.5h7.5c.61 0 1.125-.492 1.125-1.125V10.25h1.125c.61 0 1.125-.492 1.125-1.125v-7.5A1.14 1.14 0 0010.875.5zm-2.39 10.875h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h.985v5.25a1.11 1.11 0 001.125 1.125h5.25v.984c0 .094-.07.141-.14.141zm2.25-2.25h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h7.22c.07 0 .14.07.14.14v7.22c0 .093-.07.14-.14.14z\" fill=\"currentColor\"><\/path><\/svg><span data-copy-to-clipboard-text=\"true\">Copy<\/span><\/button><\/div><pre class=\"bstn-blocks-code-snippet__code-snippet-area match-braces line-numbers language-javascript\" data-language=\"javascript\" aria-readonly=\"true\"><code>const grades = [50, 78, 94, 65, 79, 82, 100, 91];\nconsole.log(grades.length); \/\/ prints 8\n \n\/\/ access the value 79 using its index value\nconsole.log(grades[4]); \/\/ prints 79. Index starts at 0.\n \n\/\/ change value at index 0 from 50 to be 86\ngrades[0] = 86\nconsole.log(grades); \/\/ prints [86, 78, 94, 65, 79, 82, 100, 91]<\/code><\/pre><\/div>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\" id=\"javascript-array-methods\"><h2 class=\"bstn-blocks-heading__heading-element\"><meta charset=\"utf-8\">JavaScript Array Methods<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">Arrays provide some useful and efficient built-in methods. Here is a\u00a0<a rel=\"noreferrer noopener\" href=\"https:\/\/developer.mozilla.org\/en-US\/docs\/Web\/JavaScript\/Reference\/Global_Objects\/Array\" target=\"_blank\">MDN Documentation on Arrays and its methods<\/a>. We will explore the most commonly used methods listed below:<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>Array.prototype.push<\/li><li>Array.prototype.pop<\/li><li>Array.prototype.includes<\/li><li>Array.prototype.indexOf<\/li><\/ul>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\" id=\"Array-Push-or-Add-Array-Elements\"><h2 class=\"bstn-blocks-heading__heading-element\"><meta charset=\"utf-8\">Array Push or Add Array Elements<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">An array element can easily be added to an existing array by using&nbsp;<code>push()<\/code>. This method will add one or more elements to the end of the array and return the length of the new array for future use.<\/p>\n\n\n\n<div class=\"wp-block-bstn-blocks-code-snippet bstn-blocks-code-snippet\" data-code-snippet=\"true\"><div class=\"bstn-blocks-code-snippet__title-bar\"><span class=\"bstn-blocks-code-snippet__title\">Code Example<\/span><button class=\"bstn-blocks-code-snippet__copy-trigger\" aria-label=\"Copy code to clipboard\" data-copy-to-clipboard=\"true\"><svg viewbox=\"0 0 12 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-code-snippet__copy-trigger-icon\"><path d=\"M10.875.5h-7.5c-.633 0-1.125.516-1.125 1.125V2.75H1.125C.492 2.75 0 3.266 0 3.875v7.5A1.11 1.11 0 001.125 12.5h7.5c.61 0 1.125-.492 1.125-1.125V10.25h1.125c.61 0 1.125-.492 1.125-1.125v-7.5A1.14 1.14 0 0010.875.5zm-2.39 10.875h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h.985v5.25a1.11 1.11 0 001.125 1.125h5.25v.984c0 .094-.07.141-.14.141zm2.25-2.25h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h7.22c.07 0 .14.07.14.14v7.22c0 .093-.07.14-.14.14z\" fill=\"currentColor\"><\/path><\/svg><span data-copy-to-clipboard-text=\"true\">Copy<\/span><\/button><\/div><pre class=\"bstn-blocks-code-snippet__code-snippet-area match-braces line-numbers language-javascript\" data-language=\"javascript\" aria-readonly=\"true\"><code>const grades = [50, 78, 94, 65, 79, 82, 100, 91];\nconsole.log(grades.length); \/\/ prints 8\n \n\/\/ add 86 to the end of grades array\n\/\/ returns new length of the array\nconst newGradesLength = grades.push(86);\n\t\nconsole.log(grades); \/\/ prints [50, 78, 94, 65, 79, 82, 100, 91, 86]\nconsole.log(newGradesLength); \/\/ 9<\/code><\/pre><\/div>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\" id=\"Array-Pop-or-Remove-Elements-to-an-Array\"><h2 class=\"bstn-blocks-heading__heading-element\"><meta charset=\"utf-8\">Array Pop or Remove Elements from an Array<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">An element can easily be removed from an existing array by using&nbsp;<code>pop()<\/code>. This method will remove an element from the end of the array and return that element.<\/p>\n\n\n\n<div class=\"wp-block-bstn-blocks-code-snippet bstn-blocks-code-snippet\" data-code-snippet=\"true\"><div class=\"bstn-blocks-code-snippet__title-bar\"><span class=\"bstn-blocks-code-snippet__title\">Code Example<\/span><button class=\"bstn-blocks-code-snippet__copy-trigger\" aria-label=\"Copy code to clipboard\" data-copy-to-clipboard=\"true\"><svg viewbox=\"0 0 12 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-code-snippet__copy-trigger-icon\"><path d=\"M10.875.5h-7.5c-.633 0-1.125.516-1.125 1.125V2.75H1.125C.492 2.75 0 3.266 0 3.875v7.5A1.11 1.11 0 001.125 12.5h7.5c.61 0 1.125-.492 1.125-1.125V10.25h1.125c.61 0 1.125-.492 1.125-1.125v-7.5A1.14 1.14 0 0010.875.5zm-2.39 10.875h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h.985v5.25a1.11 1.11 0 001.125 1.125h5.25v.984c0 .094-.07.141-.14.141zm2.25-2.25h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h7.22c.07 0 .14.07.14.14v7.22c0 .093-.07.14-.14.14z\" fill=\"currentColor\"><\/path><\/svg><span data-copy-to-clipboard-text=\"true\">Copy<\/span><\/button><\/div><pre class=\"bstn-blocks-code-snippet__code-snippet-area match-braces line-numbers language-javascript\" data-language=\"javascript\" aria-readonly=\"true\"><code>const grades = [50, 78, 94, 65, 79, 82, 100, 91];\nconsole.log(grades.length); \/\/ prints 8\n \n\/\/ remove last element 91 from the end of grades array\nconst lastElement = grades.pop();\n\t\nconsole.log(grades); \/\/ prints [50, 78, 94, 65, 79, 82, 100]\nconsole.log(grades.length); \/\/ 7\nconsole.log(lastElement); \/\/ 91<\/code><\/pre><\/div>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\"><h2 class=\"bstn-blocks-heading__heading-element\">Array Includes<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">The <code>includes()<\/code>\u00a0method is very useful to find if a certain element exists in the array. It returns\u00a0<code>true<\/code>\u00a0or\u00a0<code>false<\/code>\u00a0indicating whether the element was found or not.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<div class=\"wp-block-bstn-blocks-code-snippet bstn-blocks-code-snippet\" data-code-snippet=\"true\"><div class=\"bstn-blocks-code-snippet__title-bar\"><span class=\"bstn-blocks-code-snippet__title\">Code Example<\/span><button class=\"bstn-blocks-code-snippet__copy-trigger\" aria-label=\"Copy code to clipboard\" data-copy-to-clipboard=\"true\"><svg viewbox=\"0 0 12 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-code-snippet__copy-trigger-icon\"><path d=\"M10.875.5h-7.5c-.633 0-1.125.516-1.125 1.125V2.75H1.125C.492 2.75 0 3.266 0 3.875v7.5A1.11 1.11 0 001.125 12.5h7.5c.61 0 1.125-.492 1.125-1.125V10.25h1.125c.61 0 1.125-.492 1.125-1.125v-7.5A1.14 1.14 0 0010.875.5zm-2.39 10.875h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h.985v5.25a1.11 1.11 0 001.125 1.125h5.25v.984c0 .094-.07.141-.14.141zm2.25-2.25h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h7.22c.07 0 .14.07.14.14v7.22c0 .093-.07.14-.14.14z\" fill=\"currentColor\"><\/path><\/svg><span data-copy-to-clipboard-text=\"true\">Copy<\/span><\/button><\/div><pre class=\"bstn-blocks-code-snippet__code-snippet-area match-braces line-numbers language-javascript\" data-language=\"javascript\" aria-readonly=\"true\"><code>const grades = [50, 78, 94, 65, 79, 82, 100, 91];\n \nconsole.log(grades.includes(86)); \/\/ prints false\nconsole.log(grades.includes(91)); \/\/ prints true<\/code><\/pre><\/div>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\"><h2 class=\"bstn-blocks-heading__heading-element\">Array indexOf<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">The <code>indexOf()<\/code>\u00a0method is very useful to find if a certain element exists in the array and if so, at what index it was found. If an element is not found, the index returned will be\u00a0<code>-1<\/code>.<\/p>\n\n\n\n<div class=\"wp-block-bstn-blocks-code-snippet bstn-blocks-code-snippet\" data-code-snippet=\"true\"><div class=\"bstn-blocks-code-snippet__title-bar\"><span class=\"bstn-blocks-code-snippet__title\">Code Example<\/span><button class=\"bstn-blocks-code-snippet__copy-trigger\" aria-label=\"Copy code to clipboard\" data-copy-to-clipboard=\"true\"><svg viewbox=\"0 0 12 13\" fill=\"none\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"bstn-blocks-code-snippet__copy-trigger-icon\"><path d=\"M10.875.5h-7.5c-.633 0-1.125.516-1.125 1.125V2.75H1.125C.492 2.75 0 3.266 0 3.875v7.5A1.11 1.11 0 001.125 12.5h7.5c.61 0 1.125-.492 1.125-1.125V10.25h1.125c.61 0 1.125-.492 1.125-1.125v-7.5A1.14 1.14 0 0010.875.5zm-2.39 10.875h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h.985v5.25a1.11 1.11 0 001.125 1.125h5.25v.984c0 .094-.07.141-.14.141zm2.25-2.25h-7.22c-.093 0-.14-.047-.14-.14v-7.22c0-.07.047-.14.14-.14h7.22c.07 0 .14.07.14.14v7.22c0 .093-.07.14-.14.14z\" fill=\"currentColor\"><\/path><\/svg><span data-copy-to-clipboard-text=\"true\">Copy<\/span><\/button><\/div><pre class=\"bstn-blocks-code-snippet__code-snippet-area match-braces line-numbers language-javascript\" data-language=\"javascript\" aria-readonly=\"true\"><code>const grades = [50, 78, 94, 65, 79, 82, 100, 91];\n \nconsole.log(grades.indexOf(86)); \/\/ prints -1\nconsole.log(grades.indexOf(91)); \/\/ prints 7<\/code><\/pre><\/div>\n\n\n\n<hr class=\"wp-block-bstn-blocks-section-divider bstn-blocks-section-divider bstn-blocks-section-divider--grey bstn-blocks-section-divider--32\"\/>\n\n\n\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h3 bstn-blocks-heading--mt-0 has-text-align-left\" id=\"JavaScript-Array-Includes\"><h2 class=\"bstn-blocks-heading__heading-element\"><meta charset=\"utf-8\">JavaScript Array Object<\/h2><\/div>\n\n\n\n<p class=\"is-style-bstn-paragraph-documentation-body\">The Array object in JavaScript can store multiple values in a single variable. Array In JavaScript, arrays aren&#8217;t primitive values. They are instead Array objects that provide the ability to store an indexed collection of values as a list.\u00a0JavaScript arrays are resizable and can contain a mix of different data types.\u00a0JavaScript arrays must be accessed using nonnegative integers as indexes.\u00a0JavaScript arrays are zero-indexed.\u00a0JavaScript array-copy operations create shallow copies.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:25%\"><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-bstn-blocks-content-navigation-footer bstn-blocks-content-nav-footer bstn-blocks-content-nav-footer--article\"><div class=\"bstn-blocks-content-nav-footer__links-container\"><div class=\"bstn-blocks-content-nav-footer__link-container\"><p class=\"bstn-blocks-content-nav-footer__link-title bstn-blocks-content-nav-footer__link--desktop\">Previous<\/p><a class=\"bstn-blocks-content-nav-footer__link\" href=\"https:\/\/brainstation.io\/learn\/javascript\/boolean\"><span class=\"bstn-blocks-content-nav-footer__link-icon-wrapper bstn-blocks-content-nav-footer__link-icon-wrapper--left\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 18 18\" fill=\"none\" class=\"bstn-blocks-content-nav-footer__link-icon bstn-blocks-content-nav-footer__link-icon--left\"><path fill=\"currentColor\" d=\"M6.345 12.743a1 1 0 001.31 1.511l5.477-4.749a1 1 0 000-1.511l-5.477-4.75a1.001 1.001 0 00-1.31 1.512l4.606 3.993-4.606 3.994z\"><\/path><\/svg><\/span><span class=\"bstn-blocks-content-nav-footer__link-text bstn-blocks-content-nav-footer__link--desktop\">JavaScript Boolean<\/span><\/a><\/div><div class=\"bstn-blocks-content-nav-footer__link-container\"><p class=\"bstn-blocks-content-nav-footer__link-title\">Next<\/p><a class=\"bstn-blocks-content-nav-footer__link\" href=\"https:\/\/brainstation.io\/learn\/javascript\/object\"><span class=\"bstn-blocks-content-nav-footer__link-text\">JavaScript Object<\/span><span class=\"bstn-blocks-content-nav-footer__link-icon-wrapper bstn-blocks-content-nav-footer__link-icon-wrapper--right\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 18 18\" fill=\"none\" class=\"bstn-blocks-content-nav-footer__link-icon bstn-blocks-content-nav-footer__link-icon--right\"><path fill=\"currentColor\" d=\"M6.345 12.743a1 1 0 001.31 1.511l5.477-4.749a1 1 0 000-1.511l-5.477-4.75a1.001 1.001 0 00-1.31 1.512l4.606 3.993-4.606 3.994z\"><\/path><\/svg><\/span><\/a><\/div><\/div><\/div>\n\n\n\n<div class=\"wp-block-bstn-blocks-container bstn-blocks-container bstn-blocks-container--dark-blue bstn-blocks-container--96 bstn-blocks-container--negative-container bstn-blocks-container--overflow-hidden\"><svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewbox=\"0 0 1140 621\" fill=\"none\" class=\"bstn-blocks-container__bg-flair\"><g opacity=\"0.55\"><path stroke=\"#3C4556\" strokelinecap=\"square\" d=\"M60.026 736.434V203.02\"><\/path><path stroke=\"#3C4556\" strokelinecap=\"square\" d=\"M60.364 436.132L-120 436.131l180.364.001zm0-99.873H-120 60.364zm0-99.872H-120 60.364zM128 536.004h-248 248z\" cliprule=\"evenodd\"><\/path><path fill=\"#3C4556\" fillrule=\"evenodd\" d=\"M57.518 535.982a2.286 2.286 0 114.572 0 2.286 2.286 0 01-4.572 0zm0-99.836a2.286 2.286 0 114.572-.002 2.286 2.286 0 01-4.572.002zm0-99.837a2.286 2.286 0 114.572-.002 2.286 2.286 0 01-4.572.002zm0-99.837a2.286 2.286 0 114.572-.002 2.286 2.286 0 01-4.572.002z\" cliprule=\"evenodd\"><\/path><\/g><g opacity=\"0.55\"><path stroke=\"#3C4556\" strokelinecap=\"square\" d=\"M979.195-28.206V397.98m81.185-524.745V397.98\"><\/path><path stroke=\"#3C4556\" strokelinecap=\"square\" d=\"M1141.45 168.46H964h177.45zm0 98.334H964h177.45zm0 98.333H964h177.45zm66.55-295H964h244z\" cliprule=\"evenodd\"><\/path><path fill=\"#3C4556\" fillrule=\"evenodd\" d=\"M1138.66 70.148a2.244 2.244 0 104.49 0 2.246 2.246 0 10-4.49-.001zm-80.21 0c0 1.243 1.01 2.251 2.25 2.251s2.25-1.008 2.25-2.251c0-1.243-1.01-2.251-2.25-2.251s-2.25 1.008-2.25 2.25zm-81.707 0a2.25 2.25 0 104.5.004 2.25 2.25 0 00-4.5-.005zm81.707 98.299a2.252 2.252 0 002.25 2.251 2.252 2.252 0 000-4.503 2.253 2.253 0 00-2.25 2.252zm-81.707 0a2.25 2.25 0 104.498 0 2.25 2.25 0 00-2.249-2.252 2.25 2.25 0 00-2.249 2.252zm161.917-.001a2.244 2.244 0 104.49 0 2.246 2.246 0 10-4.49 0zm0 98.299a2.244 2.244 0 104.49 0 2.246 2.246 0 10-4.49 0zm-80.21 0c0 1.243 1.01 2.251 2.25 2.251s2.25-1.008 2.25-2.251c0-1.243-1.01-2.251-2.25-2.251s-2.25 1.008-2.25 2.251zm-81.707 0a2.25 2.25 0 104.5.002 2.25 2.25 0 00-4.5-.002zm81.707 98.299c0 1.243 1.01 2.251 2.25 2.251s2.25-1.008 2.25-2.251c0-1.243-1.01-2.251-2.25-2.251s-2.25 1.008-2.25 2.251zm-81.707 0a2.25 2.25 0 104.5.002 2.25 2.25 0 00-4.5-.002zm161.917 0a2.244 2.244 0 104.49 0 2.246 2.246 0 10-4.49 0z\" cliprule=\"evenodd\"><\/path><\/g><\/svg><div class=\"bstn-blocks-container__wrapper bstn-blocks-container__wrapper--readable-width bstn-blocks-container__wrapper--negative-container\">\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-2 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-bstn-blocks-heading bstn-blocks-heading bstn-blocks-heading--h2 has-text-align-left bstn-blocks-heading--divider\"><h2 class=\"bstn-blocks-heading__heading-element\"><meta charset=\"utf-8\">Learn JavaScript Today<\/h2><\/div>\n\n\n\n<p><meta charset=\"utf-8\">Get hands-on experience writing code with interactive tutorials in our free online learning platform. <\/p>\n\n\n\n<div style=\"height:16px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<ul class=\"wp-block-list is-style-kg-list-checklist-alternate\"><li>Free and fun<\/li><li>Designed for beginners<\/li><li>No downloads or setup required<\/li><\/ul>\n\n\n\n<div style=\"height:16px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-bstn-button-primary\"><a class=\"wp-block-button__link\" href=\"https:\/\/brainstation.io\/learn\/javascript\">Get Started<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-video\"><video autoplay loop muted src=\"https:\/\/d3ghupt9z9s6o0.cloudfront.net\/app\/uploads\/2022\/04\/13110639\/Javascript-promo-clip.mp4\"><\/video><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"<p>JavaScript arrays are collections of items. These items can be of the same type or different but arrays provide a way to group them together into a common collection. Since a JavaScript array is a collection, it is stored and used differently than other primitive data types in JavaScript. Array values are indexed which means [&hellip;]<\/p>\n","protected":false},"featured_media":0,"parent":129957,"menu_order":0,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-130045","codex-reference","type-codex-reference","status-publish","format-standard","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/codex-reference\/130045","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/codex-reference"}],"about":[{"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/types\/codex-reference"}],"version-history":[{"count":9,"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/codex-reference\/130045\/revisions"}],"predecessor-version":[{"id":133255,"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/codex-reference\/130045\/revisions\/133255"}],"up":[{"embeddable":true,"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/codex-reference\/129957"}],"wp:attachment":[{"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/media?parent=130045"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/categories?post=130045"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/brainstation.io\/wp\/api\/wp\/v2\/tags?post=130045"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}