{"id":7818,"date":"2022-11-11T09:59:37","date_gmt":"2022-11-11T09:59:37","guid":{"rendered":"https:\/\/www.jquery-az.com\/?p=7818"},"modified":"2022-11-11T09:59:37","modified_gmt":"2022-11-11T09:59:37","slug":"cpp-double","status":"publish","type":"post","link":"https:\/\/www.jquery-az.com\/cpp-double\/","title":{"rendered":"C++ Double [Declaration, Limits, size etc.] with 5 Examples"},"content":{"rendered":"<h3><strong>What is C++ Double data type?<\/strong><\/h3>\n<ul>\n<li>The double is among one of the available data types in C++ like <a href=\"\/cpp-float\/\">float<\/a>, int, <a href=\"\/cpp-char-data-type\/\">char<\/a> etc.<\/li>\n<li>Double data type allows storing bigger floating point numbers (decimal numbers) than the <a href=\"\/cpp-float\/\">float data type<\/a>.<\/li>\n<li>It takes<strong> eight bytes (64 bits)<\/strong> in the memory whereas float takes <strong>four<\/strong> bytes.<\/li>\n<li>Generally, it\u2019s precision is 15 digits.<\/li>\n<\/ul>\n<h3><strong>How to declare a double variable in C++?<\/strong><\/h3>\n<p>You may declare double variables in these ways:<\/p>\n<blockquote><p>double var;<\/p>\n<p>double var, var2, var3;<\/p>\n<p>double var = 500.987678767;<\/p>\n<p>double var = -500.877878787;<\/p>\n<p>double var = 500;<\/p>\n<p>float var = 87; \/\/Declaring a float type variable without suffix <strong>f or F<\/strong> is taken as double type as well.<\/p><\/blockquote>\n<h3><strong>C++ Program for declaring and using double type variables<\/strong><\/h3>\n<p>In this C++ program, we will create a few double type variables and display their values by using <a href=\"\/cpp-cout\/\">cout<\/a>. Have a look:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\">#include&lt;iostream&gt;\r\n\r\nusing namespace std;\r\n\r\nint main(){\r\n\r\n\/\/ Declaring and assigning float variables\r\n\r\ndouble d1 = 30.0;\r\ndouble d2 = -30.5;\r\ndouble d3 = 25.994524;\r\ndouble d4 = 4E-6; \/\/An Exponential Number\r\n\r\n\/\/Displaying Double variable values\r\n\u00a0cout &lt;&lt; \"First Double Variable Value\u00a0 = \" &lt;&lt; d1 &lt;&lt; endl;\r\n\r\n\u00a0cout &lt;&lt; \"Second Double Variable Value\u00a0 = \" &lt;&lt; d2 &lt;&lt; endl;\r\n\r\n\u00a0cout &lt;&lt; \"Third Double Variable Value\u00a0 = \" &lt;&lt; d3 &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Fourth Double Variable Value\u00a0 = \" &lt;&lt; d4 &lt;&lt; endl;\r\n\r\nreturn 1;\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-7819\" src=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_1-CPP-double.jpg\" alt=\"CPP-double\" width=\"444\" height=\"131\" srcset=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_1-CPP-double.jpg 444w, https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_1-CPP-double-300x89.jpg 300w\" sizes=\"(max-width: 444px) 100vw, 444px\" \/><\/p>\n<h3><strong>Check the memory size of double variables example<\/strong><\/h3>\n<p>As mentioned earlier, a double variable takes eight bytes in memory. The example below shows the actual size by using the sizeof() function.<\/p>\n<p><strong>See the program and its output below:<\/strong><\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\">#include&lt;iostream&gt;\r\n\r\nusing namespace std;\r\n\r\nint main(){\r\n\r\n\/\/ Declaring and assigning float variables\r\n\r\ndouble d1 = 30.0;\r\ndouble d2 = -30.5;\r\ndouble d3 = 25.994524;\r\ndouble d4 = 4E-6; \/\/An Exponential Number\r\n\r\n\/\/Displaying Double variable values\r\n\r\n\u00a0cout &lt;&lt; \"First Double Variable Size\u00a0 = \" &lt;&lt; sizeof(d1) &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Second Double Variable Size\u00a0 = \" &lt;&lt; sizeof(d2) &lt;&lt; endl;\r\n cout &lt;&lt; \"Third Double Variable Size\u00a0 = \" &lt;&lt; sizeof(d3) &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Fourth Double Variable Size\u00a0 = \" &lt;&lt; sizeof(d4) &lt;&lt; endl;\r\n\r\nreturn 1;\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-7820\" src=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_2-CPP-double-size.jpg\" alt=\"CPP-double-size\" width=\"469\" height=\"131\" srcset=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_2-CPP-double-size.jpg 469w, https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_2-CPP-double-size-300x84.jpg 300w\" sizes=\"(max-width: 469px) 100vw, 469px\" \/><\/p>\n<h3><strong>Checking the minimum and maximum limits of the double type variables example<\/strong><\/h3>\n<p>The example below shows using the <strong><em>numeric_limits<\/em><\/strong> to check the minimum and maximum limits of the double type variables. You have to include the <strong>&lt;limits&gt;<\/strong> in the header.<\/p>\n<p>Note that, the output varies from compiler to compiler \u2013 where you execute this code:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\">#include &lt;iostream&gt;\r\n\r\n#include &lt;limits&gt;\r\n\r\nusing namespace std;\r\n\r\nint main(){\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"The Max and Min Double Limit:\" &lt;&lt; endl;\r\n\u00a0\u00a0 cout &lt;&lt; \"min: \" &lt;&lt; numeric_limits&lt;double&gt;::min() &lt;&lt; endl;\r\n\u00a0\u00a0 cout &lt;&lt; \"max: \" &lt;&lt; numeric_limits&lt;double&gt;::max() &lt;&lt; \"\\n\\n\";\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"The Max and Min Float Limit:\" &lt;&lt; endl;\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"min: \" &lt;&lt; numeric_limits&lt;float&gt;::min() &lt;&lt; endl;\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"max: \" &lt;&lt; numeric_limits&lt;float&gt;::max() &lt;&lt; \"\\n\\n\";\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"The Max and Min Long Double Limit:\" &lt;&lt; endl;\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"min: \" &lt;&lt; numeric_limits&lt;long double&gt;::min() &lt;&lt; endl;\r\n\r\n\u00a0\u00a0 cout &lt;&lt; \"max: \" &lt;&lt; numeric_limits&lt;long double&gt;::max() &lt;&lt; \"\\n\\n\";\r\n\r\nreturn 1;\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-7821\" src=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_3-CPP-double-limits.jpg\" alt=\"CPP-double-limits\" width=\"451\" height=\"207\" srcset=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_3-CPP-double-limits.jpg 451w, https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_3-CPP-double-limits-300x138.jpg 300w\" sizes=\"(max-width: 451px) 100vw, 451px\" \/><\/p>\n<h3><strong>Checking and comparing the precision of double types<\/strong><\/h3>\n<p>The following example checks the precision of double type variables and compares it with other floating type data types like float and long double.<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\">#include&lt;iostream&gt;\r\n#include&lt;cstdlib&gt;\r\n\r\nusing namespace std;\r\n\r\nint main(){\r\n\r\n\/\/ Declaring and assigning floating types variables\r\n\r\ndouble dbl1 = 50.8451425421425;\r\n\r\nfloat flt1 = 5.8451425421425f;\r\n\r\nlong double ld1 = 5.8451425421425L;\r\n\r\n\/\/Displaying variable size\r\n\u00a0cout &lt;&lt; \"Double Variable\u00a0 = \" &lt;&lt; dbl1 &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Float Variable\u00a0 = \" &lt;&lt; flt1 &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Long Double Variable\u00a0 = \" &lt;&lt; ld1 &lt;&lt; endl;\r\n\r\nreturn 1;\r\n\r\n}<\/pre>\n<p><strong>Output:<\/strong><\/p>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-7822\" src=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_4-CPP-double-precision.jpg\" alt=\"CPP-double-precision\" width=\"434\" height=\"109\" srcset=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_4-CPP-double-precision.jpg 434w, https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_4-CPP-double-precision-300x75.jpg 300w\" sizes=\"(max-width: 434px) 100vw, 434px\" \/><\/p>\n<p><strong>Now let us use the setprecision() function and see the result<\/strong><\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"cpp\">#include&lt;iostream&gt;\r\n#include &lt;iomanip&gt;\r\n#include&lt;cstdlib&gt;\r\n\r\nusing namespace std;\r\n\r\nint main(){\r\n\r\n\/\/ Declaring and assigning floating types variables\r\n\r\ndouble dbl1 = 50.8451425421425;\r\nfloat flt1 = 5.8451425421425f;\r\nlong double ld1 = 5.8451425421425L;\r\n\r\n\/\/Setting precision\r\n\r\ncout &lt;&lt; setprecision(11);\r\n\r\n\/\/Displaying variable size\r\n\r\n\u00a0cout &lt;&lt; \"Double Variable\u00a0 = \" &lt;&lt; dbl1 &lt;&lt; endl;\r\n\r\n\u00a0cout &lt;&lt; \"Float Variable\u00a0 = \" &lt;&lt; flt1 &lt;&lt; endl;\r\n\u00a0cout &lt;&lt; \"Long Double Variable\u00a0 = \" &lt;&lt; ld1 &lt;&lt; endl;\r\n\r\nreturn 1;\r\n\r\n}<\/pre>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"aligncenter size-full wp-image-7823\" src=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_5-CPP-double-set-precisi.jpg\" alt=\"CPP-double-set-precisi\" width=\"451\" height=\"108\" srcset=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_5-CPP-double-set-precisi.jpg 451w, https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_5-CPP-double-set-precisi-300x72.jpg 300w\" sizes=\"(max-width: 451px) 100vw, 451px\" \/><\/p>\n<p>You saw, the values for double and long double are displayed correctly with the 11 precision setting. However, the float is showing garbage value after 7.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The double is among one of the available data types in C++ like float, int, char etc.<br \/>\nDouble data type allows storing bigger floating point numbers (decimal numbers) than the float data type.<\/p>\n","protected":false},"author":1,"featured_media":7822,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[140],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>C++ Double [Declaration, Limits, size etc.] with 5 Examples<\/title>\n<meta name=\"description\" content=\"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.jquery-az.com\/cpp-double\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"C++ Double [Declaration, Limits, size etc.] with 5 Examples\" \/>\n<meta property=\"og:description\" content=\"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.jquery-az.com\/cpp-double\/\" \/>\n<meta property=\"article:published_time\" content=\"2022-11-11T09:59:37+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_4-CPP-double-precision.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"434\" \/>\n\t<meta property=\"og:image:height\" content=\"109\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"jqueryaz\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"jqueryaz\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.jquery-az.com\/cpp-double\/\",\"url\":\"https:\/\/www.jquery-az.com\/cpp-double\/\",\"name\":\"C++ Double [Declaration, Limits, size etc.] with 5 Examples\",\"isPartOf\":{\"@id\":\"https:\/\/www.jquery-az.com\/#website\"},\"datePublished\":\"2022-11-11T09:59:37+00:00\",\"dateModified\":\"2022-11-11T09:59:37+00:00\",\"author\":{\"@id\":\"https:\/\/www.jquery-az.com\/#\/schema\/person\/c3f75f86b1c65bf0b93fc46f629fcad3\"},\"description\":\"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.\",\"breadcrumb\":{\"@id\":\"https:\/\/www.jquery-az.com\/cpp-double\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.jquery-az.com\/cpp-double\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.jquery-az.com\/cpp-double\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/www.jquery-az.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"C++ Double [Declaration, Limits, size etc.] with 5 Examples\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.jquery-az.com\/#website\",\"url\":\"https:\/\/www.jquery-az.com\/\",\"name\":\"\",\"description\":\"PHP, Bootstrap, jQuery, CSS, Python, Java and others\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/www.jquery-az.com\/?s={search_term_string}\"},\"query-input\":\"required name=search_term_string\"}],\"inLanguage\":\"en-US\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.jquery-az.com\/#\/schema\/person\/c3f75f86b1c65bf0b93fc46f629fcad3\",\"name\":\"jqueryaz\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/www.jquery-az.com\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/e2a3743b4da71bd52984e02bd5c3280c?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/e2a3743b4da71bd52984e02bd5c3280c?s=96&d=mm&r=g\",\"caption\":\"jqueryaz\"}}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"C++ Double [Declaration, Limits, size etc.] with 5 Examples","description":"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.jquery-az.com\/cpp-double\/","og_locale":"en_US","og_type":"article","og_title":"C++ Double [Declaration, Limits, size etc.] with 5 Examples","og_description":"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.","og_url":"https:\/\/www.jquery-az.com\/cpp-double\/","article_published_time":"2022-11-11T09:59:37+00:00","og_image":[{"width":434,"height":109,"url":"https:\/\/www.jquery-az.com\/wp-content\/uploads\/2022\/10\/23_4-CPP-double-precision.jpg","type":"image\/jpeg"}],"author":"jqueryaz","twitter_misc":{"Written by":"jqueryaz","Est. reading time":"4 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.jquery-az.com\/cpp-double\/","url":"https:\/\/www.jquery-az.com\/cpp-double\/","name":"C++ Double [Declaration, Limits, size etc.] with 5 Examples","isPartOf":{"@id":"https:\/\/www.jquery-az.com\/#website"},"datePublished":"2022-11-11T09:59:37+00:00","dateModified":"2022-11-11T09:59:37+00:00","author":{"@id":"https:\/\/www.jquery-az.com\/#\/schema\/person\/c3f75f86b1c65bf0b93fc46f629fcad3"},"description":"The double is among one of the available data types in C++ like float, int, char etc.Double data type allows storing bigger floating point numbers (decimal numbers) than the float data type.","breadcrumb":{"@id":"https:\/\/www.jquery-az.com\/cpp-double\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.jquery-az.com\/cpp-double\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.jquery-az.com\/cpp-double\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.jquery-az.com\/"},{"@type":"ListItem","position":2,"name":"C++ Double [Declaration, Limits, size etc.] with 5 Examples"}]},{"@type":"WebSite","@id":"https:\/\/www.jquery-az.com\/#website","url":"https:\/\/www.jquery-az.com\/","name":"","description":"PHP, Bootstrap, jQuery, CSS, Python, Java and others","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.jquery-az.com\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.jquery-az.com\/#\/schema\/person\/c3f75f86b1c65bf0b93fc46f629fcad3","name":"jqueryaz","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.jquery-az.com\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/e2a3743b4da71bd52984e02bd5c3280c?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/e2a3743b4da71bd52984e02bd5c3280c?s=96&d=mm&r=g","caption":"jqueryaz"}}]}},"_links":{"self":[{"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/posts\/7818"}],"collection":[{"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/comments?post=7818"}],"version-history":[{"count":2,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/posts\/7818\/revisions"}],"predecessor-version":[{"id":7865,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/posts\/7818\/revisions\/7865"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/media\/7822"}],"wp:attachment":[{"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/media?parent=7818"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/categories?post=7818"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.jquery-az.com\/wp-json\/wp\/v2\/tags?post=7818"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}