{"id":12894,"date":"2022-10-02T08:41:48","date_gmt":"2022-10-02T03:11:48","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/"},"modified":"2022-10-02T08:41:48","modified_gmt":"2022-10-02T03:11:48","slug":"solved-how-to-declare-a-pointer-to-an-array-of-pointer","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/","title":{"rendered":"[Solved] How to declare a pointer to an array of pointer"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div id=\"answer-52801799\" class=\"answer js-answer accepted-answer js-accepted-answer\" data-answerid=\"52801799\" data-parentid=\"52801598\" data-score=\"1\" data-position-on-page=\"1\" data-highest-scored=\"1\" data-question-has-accepted-highest-score=\"1\" itemprop=\"acceptedAnswer\" itemscope itemtype=\"https:\/\/schema.org\/Answer\">\n<div class=\"post-layout\">\n<div class=\"votecell post-layout--left\"><\/div>\n<div class=\"answercell post-layout--right\">\n<div class=\"s-prose js-post-body\" itemprop=\"text\">\n<blockquote>\n<p>I have a task to create an array of pointers to structure<\/p>\n<\/blockquote>\n<p>You need two &#8220;sizes&#8221;: <\/p>\n<ol>\n<li>The number of pointers<\/li>\n<li>The size of the struct <\/li>\n<\/ol>\n<p>You only pass one. <\/p>\n<p>So fix your code for example like this<\/p>\n<pre><code>#include &lt;stdlib.h&gt; \/* for malloc(), free() *\/\n\nvoid create1(void *** pppv, size_t n, size_t s)\n{\n  assert(NULL != pppv);\n\n  *pppv = malloc(n * sizeof **pppv);\n\n  if (NULL != *pppv)\n  {\n    for (size_t i = 0; i &lt; n; ++i)\n    {\n      (*pppv)[i] = malloc(s);\n\n       if (NULL == (*pppv)[i])\n       {\n         \/* Failed to completely allocate what has been requested, \n            so clean up *\/\n         for (--i; i &gt;= 0; --i)\n         {\n           free((*pppv)[i]);\n         }\n\n         free(*pppv);\n\n         *pppv = NULL;\n\n         break;\n       }\n    }\n  }\n}\n<\/code><\/pre>\n<p>Use it like this:<\/p>\n<pre><code>#include &lt;stdlib.h&gt; \/* for size_t, free(), exit(), EXIT_FAILURE *\/\n#include &lt;stdio.h&gt; \/* for fputs() *\/\n\nvoid create1(void ***, size_t, size_t);\n\nstruct my_struct\n{\n  int i;\n  ... \/* more elements here *\/\n}\n\n#define N (42) \/* Number of elements *\/\n\nint main(void)\n{\n  struct my_struct ** pps = NULL;\n\n  create1(&amp;pps, N, sizeof **pps);\n  if (NULL == pps)\n  {\n    fputs(stderr, \"create1() failed\\n\", stderr);\n    exit(EXIT_FAILURE);\n  }\n\n  \/* use array pps[0..N]-&gt;i here *\/\n\n  \/*Clean up *\/\n\n  for (size_t i = 0; i &lt; N; --i)\n  {\n    free(pps[i]);\n  }\n\n  free(pps);\n}\n<\/code><\/pre>\n<\/p><\/div>\n<div class=\"mt24\"><\/div>\n<\/div>\n<p>            <span class=\"d-none\" itemprop=\"commentCount\"><\/span> <\/p><\/div>\n<\/div>\n<p>[ad_2]<\/p>\n<p>solved How to declare a pointer to an array of pointer <\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] I have a task to create an array of pointers to structure You need two &#8220;sizes&#8221;: The number of pointers The size of the struct You only pass one. So fix your code for example like this #include &lt;stdlib.h&gt; \/* for malloc(), free() *\/ void create1(void *** pppv, size_t n, size_t s) { assert(NULL &#8230; <a title=\"[Solved] How to declare a pointer to an array of pointer\" class=\"read-more\" href=\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\" aria-label=\"More on [Solved] How to declare a pointer to an array of pointer\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[320],"tags":[361,324,712],"class_list":["post-12894","post","type-post","status-publish","format-standard","hentry","category-solved","tag-arrays","tag-c","tag-pointers"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v26.5 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>[Solved] How to declare a pointer to an array of pointer - JassWeb<\/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:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] How to declare a pointer to an array of pointer - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] I have a task to create an array of pointers to structure You need two &#8220;sizes&#8221;: The number of pointers The size of the struct You only pass one. So fix your code for example like this #include &lt;stdlib.h&gt; \/* for malloc(), free() *\/ void create1(void *** pppv, size_t n, size_t s) { assert(NULL ... Read more\" \/>\n<meta property=\"og:url\" content=\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\" \/>\n<meta property=\"og:site_name\" content=\"JassWeb\" \/>\n<meta property=\"article:published_time\" content=\"2022-10-02T03:11:48+00:00\" \/>\n<meta name=\"author\" content=\"Kirat\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Kirat\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\"},\"author\":{\"name\":\"Kirat\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\"},\"headline\":\"[Solved] How to declare a pointer to an array of pointer\",\"datePublished\":\"2022-10-02T03:11:48+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\"},\"wordCount\":65,\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"keywords\":[\"arrays\",\"c++\",\"pointers\"],\"articleSection\":[\"Solved\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\",\"url\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\",\"name\":\"[Solved] How to declare a pointer to an array of pointer - JassWeb\",\"isPartOf\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#website\"},\"datePublished\":\"2022-10-02T03:11:48+00:00\",\"breadcrumb\":{\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/jassweb.com\/solved\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"[Solved] How to declare a pointer to an array of pointer\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/jassweb.com\/solved\/#website\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"name\":\"JassWeb\",\"description\":\"Build High-quality Websites\",\"publisher\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/jassweb.com\/solved\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/jassweb.com\/solved\/#organization\",\"name\":\"Jass Web\",\"url\":\"https:\/\/jassweb.com\/solved\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"contentUrl\":\"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png\",\"width\":693,\"height\":132,\"caption\":\"Jass Web\"},\"image\":{\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31\",\"name\":\"Kirat\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"contentUrl\":\"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586\",\"caption\":\"Kirat\"},\"sameAs\":[\"http:\/\/jassweb.com\"],\"url\":\"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"[Solved] How to declare a pointer to an array of pointer - JassWeb","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:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/","og_locale":"en_US","og_type":"article","og_title":"[Solved] How to declare a pointer to an array of pointer - JassWeb","og_description":"[ad_1] I have a task to create an array of pointers to structure You need two &#8220;sizes&#8221;: The number of pointers The size of the struct You only pass one. So fix your code for example like this #include &lt;stdlib.h&gt; \/* for malloc(), free() *\/ void create1(void *** pppv, size_t n, size_t s) { assert(NULL ... Read more","og_url":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/","og_site_name":"JassWeb","article_published_time":"2022-10-02T03:11:48+00:00","author":"Kirat","twitter_card":"summary_large_image","twitter_misc":{"Written by":"Kirat","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#article","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/"},"author":{"name":"Kirat","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31"},"headline":"[Solved] How to declare a pointer to an array of pointer","datePublished":"2022-10-02T03:11:48+00:00","mainEntityOfPage":{"@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/"},"wordCount":65,"publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"keywords":["arrays","c++","pointers"],"articleSection":["Solved"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/","url":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/","name":"[Solved] How to declare a pointer to an array of pointer - JassWeb","isPartOf":{"@id":"https:\/\/jassweb.com\/solved\/#website"},"datePublished":"2022-10-02T03:11:48+00:00","breadcrumb":{"@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/jassweb.com\/solved\/solved-how-to-declare-a-pointer-to-an-array-of-pointer\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/jassweb.com\/solved\/"},{"@type":"ListItem","position":2,"name":"[Solved] How to declare a pointer to an array of pointer"}]},{"@type":"WebSite","@id":"https:\/\/jassweb.com\/solved\/#website","url":"https:\/\/jassweb.com\/solved\/","name":"JassWeb","description":"Build High-quality Websites","publisher":{"@id":"https:\/\/jassweb.com\/solved\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/jassweb.com\/solved\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/jassweb.com\/solved\/#organization","name":"Jass Web","url":"https:\/\/jassweb.com\/solved\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/","url":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","contentUrl":"https:\/\/jassweb.com\/wp-content\/uploads\/2021\/02\/jass-website-logo-1.png","width":693,"height":132,"caption":"Jass Web"},"image":{"@id":"https:\/\/jassweb.com\/solved\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/65c9c7b7958150c0dc8371fa35dd7c31","name":"Kirat","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/jassweb.com\/solved\/#\/schema\/person\/image\/","url":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","contentUrl":"https:\/\/jassweb.com\/solved\/wp-content\/litespeed\/avatar\/1261af3c9451399fa1336d28b98ea3bb.jpg?ver=1776403586","caption":"Kirat"},"sameAs":["http:\/\/jassweb.com"],"url":"https:\/\/jassweb.com\/solved\/author\/jaspritsinghghumangmail-com\/"}]}},"_links":{"self":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/12894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/comments?post=12894"}],"version-history":[{"count":0,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/posts\/12894\/revisions"}],"wp:attachment":[{"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/media?parent=12894"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/categories?post=12894"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jassweb.com\/solved\/wp-json\/wp\/v2\/tags?post=12894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}