{"id":19596,"date":"2022-11-07T05:06:00","date_gmt":"2022-11-06T23:36:00","guid":{"rendered":"https:\/\/jassweb.com\/solved\/solved-memcpy-doesnt-copy-anything-or-not\/"},"modified":"2022-11-07T05:06:00","modified_gmt":"2022-11-06T23:36:00","slug":"solved-memcpy-doesnt-copy-anything-or-not","status":"publish","type":"post","link":"https:\/\/jassweb.com\/solved\/solved-memcpy-doesnt-copy-anything-or-not\/","title":{"rendered":"[Solved] memcpy doesn&#8217;t copy anything or not?"},"content":{"rendered":"<p> [ad_1]<br \/>\n<\/p>\n<div id=\"answer-12105461\" class=\"answer js-answer accepted-answer js-accepted-answer\" data-answerid=\"12105461\" data-parentid=\"12105362\" data-score=\"3\" data-position-on-page=\"2\" data-highest-scored=\"0\" data-question-has-accepted-highest-score=\"0\" itemprop=\"suggestedAnswer\" 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<p>Your array is not &#8220;empty&#8221;, despite your protestations. It just holds a very, very small value: Your machine uses the IEEE754 standard for representing floating points. In that standard, the word with all zeros represents the value 0.0. The next bigger word (i.e. the one obtained by adding 1 to the underlying bits) represents the next biggest floating point value, which is an extremely tiny, denormal value. When you <code>printf<\/code> this value to standard precision (6 decimal places?), it&#8217;s just rounded to zero.<\/p>\n<p>Here&#8217;s a tangentially related answer of mine on a similar question.<\/p>\n<\/p><\/div>\n<div class=\"mt24\"><\/div>\n<\/div>\n<p>            <span class=\"d-none\" itemprop=\"commentCount\">3<\/span> <\/p><\/div>\n<\/div>\n<p>[ad_2]<\/p>\n<p>solved memcpy doesn&#8217;t copy anything or not? <\/p>\n","protected":false},"excerpt":{"rendered":"<p>[ad_1] Your array is not &#8220;empty&#8221;, despite your protestations. It just holds a very, very small value: Your machine uses the IEEE754 standard for representing floating points. In that standard, the word with all zeros represents the value 0.0. The next bigger word (i.e. the one obtained by adding 1 to the underlying bits) represents &#8230; <a title=\"[Solved] memcpy doesn&#8217;t copy anything or not?\" class=\"read-more\" href=\"https:\/\/jassweb.com\/solved\/solved-memcpy-doesnt-copy-anything-or-not\/\" aria-label=\"More on [Solved] memcpy doesn&#8217;t copy anything or not?\">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":[324,1159],"class_list":["post-19596","post","type-post","status-publish","format-standard","hentry","category-solved","tag-c","tag-visual-studio-2010"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>[Solved] memcpy doesn&#039;t copy anything or not? - 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-memcpy-doesnt-copy-anything-or-not\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"[Solved] memcpy doesn&#039;t copy anything or not? - JassWeb\" \/>\n<meta property=\"og:description\" content=\"[ad_1] Your array is not &#8220;empty&#8221;, despite your protestations. It just holds a very, very small value: Your machine uses the IEEE754 standard for representing floating points. In that standard, the word with all zeros represents the value 0.0. The next bigger word (i.e. the one obtained by adding 1 to the underlying bits) represents ... 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