{"id":4857,"date":"2021-11-24T23:05:00","date_gmt":"2021-11-24T17:35:00","guid":{"rendered":"https:\/\/www.codingbroz.com\/?p=4857"},"modified":"2021-11-24T10:47:36","modified_gmt":"2021-11-24T05:17:36","slug":"cpp-program-to-find-prime-number","status":"publish","type":"post","link":"https:\/\/www.codingbroz.com\/cpp-program-to-find-prime-number\/","title":{"rendered":"C++ Program to Find Prime Number"},"content":{"rendered":"\n<p>In this post, we will learn <strong>how to find prime numbers using C++<\/strong> Programming language.<\/p>\n\n\n\n<p>A <strong>prime number<\/strong> is a natural number greater than <strong>1 <\/strong>that is not a product of two smaller natural numbers. For example: <strong>27<\/strong> is not a prime number because <strong>27 = 3 x 9<\/strong>. While <strong>17<\/strong> is a prime number because there are only two factors of <strong>17<\/strong>: <strong>1<\/strong> and <strong>17<\/strong> itself.<\/p>\n\n\n\n<p>We will find the prime numbers by checking the number of factors of a particular number. If<strong> factors > 2 <\/strong>then, it\u2019s not a prime number.<\/p>\n\n\n\n<p>So, without further ado, let\u2019s begin this tutorial.\u00a0<\/p>\n\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_65 ez-toc-wrap-left counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<label for=\"ez-toc-cssicon-toggle-item-662c40bd2689d\" class=\"ez-toc-cssicon-toggle-label\"><label class=\"ez-toc-title\">Table of Contents<\/label>\n<span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #0090ff;color:#0090ff\" 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: #0090ff;color:#0090ff\" 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 type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-662c40bd2689d\" checked \/><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:\/\/www.codingbroz.com\/cpp-program-to-find-prime-number\/#C_Program_to_Find_Prime_Number\" title=\"C++ Program to Find Prime Number\">C++ Program to Find Prime Number<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.codingbroz.com\/cpp-program-to-find-prime-number\/#How_Does_This_Program_Work\" title=\"How Does This Program Work ?\">How Does This Program Work ?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.codingbroz.com\/cpp-program-to-find-prime-number\/#C_Program_to_Find_Prime_Number_Using_While_Loop\" title=\"C++ Program to Find Prime Number Using While Loop\">C++ Program to Find Prime Number Using While Loop<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.codingbroz.com\/cpp-program-to-find-prime-number\/#Conclusion\" title=\"Conclusion\">Conclusion<\/a><\/li><\/ul><\/nav><\/div>\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"C_Program_to_Find_Prime_Number\"><\/span><strong>C++ Program to Find Prime Number<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ C++ Program to Find Prime Number\n#include &lt;iostream>\nusing namespace std;\n\nint main(){\n    int num, i;\n    bool flag = true;\n    \n    \/\/ Asking for input\n    cout &lt;&lt; \"Enter any positive integer: \";\n    cin >> num;\n    \n    for (i = 2; i &lt; num; ++i){\n        if (num % i == 0){\n            flag = false;\n            break;\n        }\n    }\n    if (flag == true)\n        cout &lt;&lt; num &lt;&lt; \" is a prime number.\";\n    else \n        cout &lt;&lt; num &lt;&lt; \" is not a prime number.\";\n    return 0;\n}\n<\/pre>\n\n\n\n<p><strong>Output 1<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Enter any positive integer: 17\r\n17 is a prime number.\r<\/code><\/pre>\n\n\n\n<p><strong>Output 2<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Enter any positive integer: 91\r\n91 is not a prime number.\r<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"How_Does_This_Program_Work\"><\/span><strong>How Does This Program Work ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    int num, i;\n    bool flag = true;\n<\/pre>\n\n\n\n<p>In this program, we have declared <strong>two int data type<\/strong> variables named <strong>i <\/strong>and <strong>num<\/strong>.<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    \/\/ Asking for input\n    cout &lt;&lt; \"Enter any positive integer: \";\n    cin >> num;\n<\/pre>\n\n\n\n<p>Then, the user is asked to enter a positive integer.<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    for (i = 2; i &lt; num; ++i){\n        if (num % i == 0){\n            flag = false;\n            break;\n        }\n    }\n<\/pre>\n\n\n\n<p>Then, we check whether the entered number is divisible by any number greater than <strong>2<\/strong> or not. If there is any number which is divisible by <strong>num<\/strong>, then <strong>flag<\/strong> value changes to <strong>false<\/strong>.<\/p>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">    if (flag == true)\n        cout &lt;&lt; num &lt;&lt; \" is a prime number.\";\n    else \n        cout &lt;&lt; num &lt;&lt; \" is not a prime number.\";\n<\/pre>\n\n\n\n<p>If<strong> flag = true<\/strong>, then the entered number is a <strong>prime number <\/strong>otherwise the entered number is not a prime number.\u00a0<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"C_Program_to_Find_Prime_Number_Using_While_Loop\"><\/span><strong>C++ Program to Find Prime Number Using While Loop<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\" data-enlighter-theme=\"\" data-enlighter-highlight=\"\" data-enlighter-linenumbers=\"\" data-enlighter-lineoffset=\"\" data-enlighter-title=\"\" data-enlighter-group=\"\">\/\/ C++ Program to Find Prime Number\n#include &lt;iostream>\nusing namespace std;\n\nint main(){\n    int num, i;\n    bool flag = true;\n    \n    \/\/ Asking for input\n    cout &lt;&lt; \"Enter any positive integer: \";\n    cin >> num;\n    \n    i = 2;\n    while(i &lt;= num\/2){\n        if(num % i == 0){\n            flag = false;\n            break;\n        }\n        i++;\n    }\n    if (flag == true)\n        cout &lt;&lt; num &lt;&lt; \" is a prime number.\";\n    else \n        cout &lt;&lt; num &lt;&lt; \" is not a prime number.\";\n    return 0;\n}\n<\/pre>\n\n\n\n<p><strong>Output 1<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Enter any positive integer: 97\r\n97 is a prime number.\r<\/code><\/pre>\n\n\n\n<p><strong>Output 2<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Enter any positive integer: 25\r\n25 is not a prime number.\r<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span><strong>Conclusion<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>I hope after going through this post, you understand <strong>how to find prime numbers using C++<\/strong> Programming language.<\/p>\n\n\n\n<p>If you have any doubt regarding the program, feel free to contact us in the comment section. We will be delighted to guide you.<\/p>\n\n\n\n<p><strong>Also Read:<\/strong><\/p>\n\n\n\n<ul><li><strong><a href=\"https:\/\/www.codingbroz.com\/cpp-hello-world-program\/\">C++ Hello World Program<\/a><\/strong><\/li><li><strong><a href=\"https:\/\/www.codingbroz.com\/cpp-program-to-reverse-a-string\/\">C++ Program to Reverse a String<\/a><\/strong><\/li><li><strong><a href=\"https:\/\/www.codingbroz.com\/cpp-program-to-find-area-of-rectangle\/\">C++ Program to Find Area of Rectangle<\/a><\/strong><\/li><li><strong><a href=\"https:\/\/www.codingbroz.com\/cpp-program-to-find-smallest-of-n-numbers\/\">C++ Program to Find Smallest of N Numbers<\/a><\/strong><\/li><li><strong><a href=\"https:\/\/www.codingbroz.com\/cpp-program-to-convert-cm-to-feet-and-inches\/\">C++ Program to Convert Centimeters to Feet and Inches<\/a><\/strong><\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>In this post, we will learn how to find prime numbers using C++ Programming language.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[168,358],"tags":[362,434,361],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","jetpack-related-posts":[],"_links":{"self":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/4857"}],"collection":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/comments?post=4857"}],"version-history":[{"count":3,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/4857\/revisions"}],"predecessor-version":[{"id":4860,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/posts\/4857\/revisions\/4860"}],"wp:attachment":[{"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/media?parent=4857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/categories?post=4857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codingbroz.com\/wp-json\/wp\/v2\/tags?post=4857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}