{"id":44780,"date":"2023-09-20T07:44:34","date_gmt":"2023-01-04T19:08:43","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/"},"modified":"2024-01-15T12:11:33","modified_gmt":"2024-01-15T04:11:33","slug":"44780-2","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/","title":{"rendered":""},"content":{"rendered":"<h1>Basic variable types<\/h1>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">bool<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">signed integer: int int8 int16 int 32 int64<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">unsigned integer: unint unit8 unit16 unit32 unit64 unitptr<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">byte (alias for uint8)<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">run (unicode point, alias for int32)<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">float32 float64<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">complex64 complex128<\/ul>\n<h1>integer comparison<\/h1>\n<div>\n<div class=\"post-table\">TypeDescriptionint unit uintptrat least 32 bit based on OS (32 bit on 32 bit OS, 64 bit on 64 bit OSint8<code>-128 ~ 127<\/code> ($ -2^7$ ~ $2^7-1$)unit8<code>0 ~ 255<\/code> (0 ~ $2^8-1$)int16<code>-32768 ~ 32767<\/code>unit16<code>0 ~ 65535<\/code><\/div>\n<\/div>\n<p>(if there is no any special reason, int should be used when we need a number)<\/p>\n<ul class=\"post-ul\">byte = unit8 (these types are to differentiate byte and number)<\/ul>\n<h1>Get the biggest number of a type<\/h1>\n<div>\n<div class=\"post-table\">TypeGo syntaxMeaningunint641&lt;&lt;64 &#8211; 12^64 &#8211; 1unint81&lt;&lt;8 &#8211; 12^8 &#8211; 1 = 255<\/div>\n<\/div>\n<h2>How it works?<\/h2>\n<pre class=\"post-pre\"><code><span class=\"n\">big<\/span> <span class=\"o\">=<\/span> <span class=\"m\">1<\/span> <span class=\"o\">&lt;&lt;<\/span> <span class=\"m\">100<\/span> <span class=\"c\">\/\/ shift a 1 bit left 100 places &lt;=&gt; 2^100<\/span>\r\n<span class=\"n\">small<\/span> <span class=\"o\">=<\/span> <span class=\"n\">big<\/span> <span class=\"o\">&gt;&gt;<\/span> <span class=\"m\">99<\/span> <span class=\"c\">\/\/ it right again 99 places &lt;=&gt; 2^-99, so we end up with 1&lt;&lt;1, or 2<\/span>\r\n<\/code><\/pre>\n<h1>Type conversion<\/h1>\n<pre class=\"post-pre\"><code>\r\n<span class=\"k\">var<\/span> <span class=\"n\">i<\/span> <span class=\"kt\">int<\/span> <span class=\"o\">=<\/span> <span class=\"m\">42<\/span>\r\n<span class=\"k\">var<\/span> <span class=\"n\">f<\/span> <span class=\"n\">float<\/span> <span class=\"o\">=<\/span> <span class=\"kt\">float64<\/span><span class=\"p\">(<\/span><span class=\"n\">i<\/span><span class=\"p\">)<\/span>\r\n<span class=\"k\">var<\/span> <span class=\"n\">u<\/span> <span class=\"kt\">int<\/span> <span class=\"o\">=<\/span> <span class=\"n\">unint<\/span><span class=\"p\">(<\/span><span class=\"n\">f<\/span><span class=\"p\">)<\/span>\r\n\r\n<span class=\"c\">\/\/ same as<\/span>\r\n<span class=\"n\">i<\/span> <span class=\"o\">:=<\/span> <span class=\"m\">42<\/span>\r\n<span class=\"n\">f<\/span> <span class=\"o\">:=<\/span> <span class=\"kt\">float64<\/span><span class=\"p\">(<\/span><span class=\"n\">i<\/span><span class=\"p\">)<\/span>\r\n<span class=\"n\">u<\/span> <span class=\"o\">:=<\/span> <span class=\"kt\">uint<\/span><span class=\"p\">(<\/span><span class=\"n\">f<\/span><span class=\"p\">)<\/span>\r\n<\/code><\/pre>\n<h1>init() function<\/h1>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">init() is called after package variable declaration<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">each package may have multiple init()<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">order of calling init() (in case of multiple init) is un-guaranteed<\/ul>\n<h1>main() function<\/h1>\n<p>main() is called after all init() are run<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Basic variable types bool &nbsp; signed integer: int in [&hellip;]<\/p>\n","protected":false},"author":10,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-44780","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>- Blog - Silicon Cloud<\/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:\/\/www.silicloud.com\/zh\/blog\/44780-2\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:description\" content=\"Basic variable types bool &nbsp; signed integer: int in [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:published_time\" content=\"2023-01-04T19:08:43+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-01-15T04:11:33+00:00\" \/>\n<meta name=\"author\" content=\"\u5b87, \u534e\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"\u5b87, \u534e\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/\",\"name\":\"- Blog - Silicon Cloud\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\"},\"datePublished\":\"2023-01-04T19:08:43+00:00\",\"dateModified\":\"2024-01-15T04:11:33+00:00\",\"author\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/513018e4e121d3add1b7c5de8be21458\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/\"]}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/\",\"name\":\"Blog - Silicon Cloud\",\"description\":\"\",\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/513018e4e121d3add1b7c5de8be21458\",\"name\":\"\u5b87, \u534e\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/63cd45cbc05a35fc4ff7637a163c83c4962ef58d27472726c3a3e0c9c5194f0f?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/63cd45cbc05a35fc4ff7637a163c83c4962ef58d27472726c3a3e0c9c5194f0f?s=96&d=mm&r=g\",\"caption\":\"\u5b87, \u534e\"},\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/author\/yuhua\/\"},{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/44780-2\/#local-main-organization-logo\",\"url\":\"\",\"contentUrl\":\"\",\"caption\":\"Blog - Silicon Cloud\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"- Blog - Silicon Cloud","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.silicloud.com\/zh\/blog\/44780-2\/","og_locale":"zh_CN","og_type":"article","og_description":"Basic variable types bool &nbsp; 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