{"id":212,"date":"2020-12-08T03:56:19","date_gmt":"2020-12-08T03:56:19","guid":{"rendered":"https:\/\/codeflarelimited.com\/blog\/?p=212"},"modified":"2021-05-31T05:33:02","modified_gmt":"2021-05-31T04:33:02","slug":"pure-and-impure-functions-in-javascript","status":"publish","type":"post","link":"https:\/\/codeflarelimited.com\/blog\/pure-and-impure-functions-in-javascript\/","title":{"rendered":"Pure And Impure Functions in Javascript"},"content":{"rendered":"\n<p class=\"has-large-font-size\"><strong>Pure Functions<\/strong><\/p>\n\n\n\n<p>A pure function in Javascript is one that given the same input will always return the same output and does not have any observable side effect.<\/p>\n\n\n\n<p>This means that it does not depend on or change any state outside of the function and will always return the same output value for the same input.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link\" href=\"\" target=\"_blank\" rel=\"noreferrer noopener\">Read more about functions<\/a><\/div>\n<\/div>\n\n\n\n<p>Example<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">add = (a, b) =&gt; {\nreturn a+b;\n}\nconsole.log(add(3,4)); \/\/7<\/code><\/pre>\n\n\n\n<p class=\"has-large-font-size\"><strong>Impure Functions<\/strong><\/p>\n\n\n\n<p>The outcome of an impure function on the other hand depends on any change outside of the function and will not return the same output value for the same input.<\/p>\n\n\n\n<p>Example<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code lang=\"javascript\" class=\"language-javascript\">let minimum = 21;\nlet checkAge = function(age){\nreturn age &gt; minimum;\n}\nconsole.log(checkAge(22)); \/\/True<\/code><\/pre>\n\n\n\n<p>In the above example, the outcome of the program depends on the value assigned to the <em>minimum <\/em>variable. If that variable changes, the function will not return the same output value even if the input remains constant.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\"><\/div>\n\n\n\n<p><strong>THE END<\/strong><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Pure Functions A pure function in Javascript is one that given the same input will always return the<\/p>\n","protected":false},"author":1,"featured_media":214,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[11],"tags":[60,59,58],"class_list":["post-212","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript","tag-functions","tag-impure-functions","tag-pure-functions"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - 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