{"id":327,"date":"2013-07-26T20:43:31","date_gmt":"2013-07-26T12:43:31","guid":{"rendered":"http:\/\/coderbee.net\/?p=327"},"modified":"2013-07-26T20:43:31","modified_gmt":"2013-07-26T12:43:31","slug":"go%e8%af%ad%e8%a8%80%e5%9f%ba%e7%a1%802","status":"publish","type":"post","link":"https:\/\/coderbee.net\/index.php\/go\/20130726\/327","title":{"rendered":"Go\u8bed\u8a00\u57fa\u78402"},"content":{"rendered":"<h2>\u51fd\u6570<\/h2>\n<h3>\u5b9a\u4e49\uff1a<\/h3>\n<p><a href=\"\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/func-define-syntax.png\"><img loading=\"lazy\" decoding=\"async\" src=\"\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/func-define-syntax-300x219.png\" alt=\"func-define-syntax\" width=\"300\" height=\"219\" class=\"alignnone size-medium wp-image-332\" srcset=\"https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/func-define-syntax-300x219.png 300w, https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/func-define-syntax-624x456.png 624w, https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/func-define-syntax.png 705w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><br \/>\n<!--more--><\/p>\n<h3>\u4f5c\u7528\u57df<\/h3>\n<p>\u5728Go\u4e2d\uff0c\u5b9a\u4e49\u5728\u51fd\u6570\u5916\u7684\u53d8\u91cf\u662f\u5168\u5c40\u7684\uff0c\u5b9a\u4e49\u5728\u51fd\u6570\u5185\u90e8\u662f\u5c40\u90e8\u7684\u3002\u5982\u679c\u5168\u5c40\u4e0e\u5c40\u90e8\u53d8\u91cf\u540c\u540d\uff0c\u5c40\u90e8\u53d8\u91cf\u5c06\u8986\u76d6\u5168\u5c40\u53d8\u91cf\u3002<\/p>\n<h3>\u4f20\u503c\u4e0e\u4f20\u6307\u9488<\/h3>\n<p>Go\u4e2d\u53c2\u6570\u4f20\u9012\u662f\u503c\u4f20\u9012\uff0c\u5f53\u4f20\u4e00\u4e2a\u53c2\u6570\u503c\u5230\u88ab\u8c03\u7528\u51fd\u6570\u91cc\u7684\u65f6\u5019\uff0c\u5b9e\u9645\u4e0a\u662f\u62f7\u8d1d\u4e86\u8fd9\u4e2a\u53c2\u6570\u503c\u3002<\/p>\n<h3>\u53d8\u53c2<\/h3>\n<p><code>func myfunc(arg ...int) {}<\/code>\uff1a\u53d8\u53c2\u7684\u7c7b\u578b\u90fd\u76f8\u540c\uff0c\u5728\u8fd9\u4e2a\u4f8b\u5982\u7684\u51fd\u6570\u4f53\u4e2d\uff0c\u53d8\u91cfarg\u662f\u4e00\u4e2aint\u7c7b\u578b\u7684slice\u3002<\/p>\n<p>\u5982\u679c\u4e0d\u6307\u5b9a\u53d8\u53c2\u7684\u7c7b\u578b\uff0c\u9ed8\u8ba4\u662f\u7a7a\u7684\u63a5\u53e3<code>interface{}<\/code>\u3002<\/p>\n<p>\u4f20\u9012\u53d8\u53c2\uff1a<\/p>\n<pre><code>\nfunc myfunc(arg ...int) {\n    myfunc2(arg...)                \/\/ \u6309\u539f\u6837\u4f20\u9012\n    myfunc2(arg[:2]...)            \/\/ \u4f20\u9012\u7247\u6bb5\n}\n<\/code><\/pre>\n<h3>\u591a\u4e2a\u8fd4\u56de\u503c<\/h3>\n<p>Go\u51fd\u6570\u7684\u8fd4\u56de\u503c\u6216\u8005\u7ed3\u679c\u53c2\u6570\u53ef\u4ee5\u6307\u5b9a\u4e00\u4e2a\u540d\u5b57\uff0c\u5e76\u4e14\u50cf\u539f\u59cb\u7684\u53d8\u91cf\u90a3\u6837\u4f7f\u7528\uff0c\u5c31\u50cf\u8f93\u5165\u53c2\u6570\u90a3\u6837\u3002<\/p>\n<p>\u5b98\u65b9\u5efa\u8bae\uff1a\u6700\u597d\u547d\u540d\u8fd4\u56de\u503c\uff0c\u56e0\u4e3a\u4e0d\u547d\u540d\u8fd4\u56de\u503c\uff0c\u867d\u7136\u4f7f\u5f97\u4ee3\u7801\u66f4\u52a0\u7b80\u6d01\u4e86\uff0c\u4f46\u662f\u4f1a\u9020\u6210\u751f\u6210\u7684\u6587\u6863\u53ef\u8bfb\u6027\u5dee\u3002<\/p>\n<p>\u5982\u679c\u5bf9\u5176\u547d\u540d\uff0c\u5728\u51fd\u6570\u5f00\u59cb\u65f6\uff0c\u5b83\u4eec\u4f1a\u7528\u5176\u7c7b\u578b\u7684\u96f6\u503c\u521d\u59cb\u5316\uff1b\u5982\u679c\u51fd\u6570\u5728\u4e0d\u52a0\u5165\u53c2\u6570\u7684\u60c5\u51b5\u4e0b\u6267\u884c\u4e86return\u8bed\u53e5\uff0c\u7ed3\u679c\u53c2\u6570\u7684\u5f53\u524d\u503c\u4f1a\u4f5c\u4e3a\u8fd4\u56de\u503c\u8fd4\u56de\u3002<\/p>\n<h2>\u51fd\u6570\u4f5c\u4e3a\u503c<\/h2>\n<p>\u5728Go\u4e2d\u51fd\u6570\u4e5f\u662f\u4e00\u79cd\u53d8\u91cf\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7<code>type<\/code>\u6765\u5b9a\u4e49\u5b83\uff0c\u5b83\u7684\u7c7b\u578b\u5c31\u662f\u6240\u6709\u62e5\u6709\u76f8\u540c\u7684\u53c2\u6570\uff0c\u76f8\u540c\u7684\u8fd4\u56de\u503c\u7684\u4e00\u79cd\u7c7b\u578b\uff1a<br \/>\n<code>type typeName func(input1 inputType1 , input2 inputType2 [, ...]) (result1 resultType1 [, ...])<\/code><\/p>\n<pre><code>\npackage main\nimport \"fmt\"\n\ntype testInt func(int) bool      \/\/ \u58f0\u660e\u4e86\u4e00\u4e2a\u51fd\u6570\u7c7b\u578b\n\nfunc isOdd(integer int) bool {\n    if integer%2 == 0 {\n        return false\n    }\n    return true\n}\n\nfunc isEven(integer int) bool {\n    if integer%2 == 0 {\n        return true\n    }\n    return false\n}\n\n\/\/ \u58f0\u660e\u7684\u51fd\u6570\u7c7b\u578b\u5728\u8fd9\u4e2a\u5730\u65b9\u5f53\u505a\u4e86\u4e00\u4e2a\u53c2\u6570\nfunc filter(slice []int, f testInt) []int {\n    var result []int\n    for _, value := range slice {\n        if f(value) {\n            result = append(result, value)\n        }\n    }\n    return result\n}\n\nfunc main(){\n    slice := []int {1, 2, 3, 4, 5, 7}\n    fmt.Println(\"slice = \", slice)\n    odd := filter(slice, isOdd)              \/\/ \u51fd\u6570\u5f53\u505a\u503c\u6765\u4f20\u9012\u4e86\n    fmt.Println(\"Odd elements of slice are: \", odd)\n    even := filter(slice, isEven)            \/\/ \u51fd\u6570\u5f53\u505a\u503c\u6765\u4f20\u9012\u4e86\n    fmt.Println(\"Even elements of slice are: \", even)\n}\n<\/code><\/pre>\n<h2>\u5ef6\u8fdf\u6267\u884c<\/h2>\n<p><code>defer<\/code>\u5173\u952e\u5b57\u540e\u9762\u6307\u5b9a\u7684\u51fd\u6570\u5728\u51fd\u6570\u9000\u51fa\u524d\u8c03\u7528\u3002\u5ef6\u8fdf\u7684\u51fd\u6570\u662f\u6309\u7167\u540e\u8fdb\u5148\u51fa\uff08LIFO\uff09\u7684\u987a\u5e8f\u6267\u884c\u3002<\/p>\n<p>\u5229\u7528defer\u751a\u81f3\u53ef\u4ee5\u4fee\u6539\u8fd4\u56de\u503c\u3002<\/p>\n<pre><code>\ndefer func(x int) {\n        \/\/ \u5728\u8fd9\u91cc\u533f\u540d\u51fd\u6570\u5185\u90e8\uff0c\u53ef\u4ee5\u8bbf\u95ee\u5916\u56f4\u51fd\u6570\u7684\u8fd4\u56de\u503c\u3002\n} (5)             \/\/ () \u5728\u8fd9\u91cc\u662f\u5fc5\u987b\u7684\u3002\n<\/code><\/pre>\n<h2>\u81ea\u5b9a\u4e49\u7c7b\u578b struct<\/h2>\n<p>\u5728Go\u4e2d\u4e5f\u53ef\u4ee5\u58f0\u660e\u65b0\u7684\u7c7b\u578b\uff0c\u4f5c\u4e3a\u5176\u4ed6\u7c7b\u578b\u7684\u5c5e\u6027\u6216\u5b57\u6bb5\u7684\u5bb9\u5668\u3002<\/p>\n<h3>\u5b9a\u4e49<\/h3>\n<pre><code>\ntype Student struct {\n   name string\n   age int\n}\n\n\/\/ \u7ed9\u81ea\u5b9a\u4e49\u7c7b\u578b\u6dfb\u52a0\u65b9\u6cd5\nfunc (s *Student)show() {\n    fmt.Println(\"i'am \" + s.name)\n}\n<\/code><\/pre>\n<p><strong>\u6ce8\u610f\uff1a<\/strong><br \/>\nstruct \u4e0d\u5141\u8bb8\u9012\u5f52\u5b9a\u4e49\u6216\u5b9a\u4e49\u91cc\u5305\u542b\u5faa\u73af\u3002\u4e0b\u9762\u4e24\u79cd\u60c5\u5f62\u90fd\u662f\u7f16\u8bd1\u4e0d\u901a\u8fc7\u7684\u3002<\/p>\n<pre><code language=\"go\">\n\/\/  \u5f62\u5f0f\u4e00\ntype  Node  struct {\n     parent,  lChild,  rChild  Node\n     key  int\n}\n\n\n\/\/  \u5f62\u5f0f\u4e8c\ntype  Node  struct {\n     parent,  lChild,  rChild  BinaryTree\n     key  int\n}\n\ntype  BinaryTreestruct {\n     node  Node\n}\n<\/code><\/pre>\n<h3>\u5b9e\u4f8b\u5316<\/h3>\n<p>\u7c7b\u578b\u7684\u521d\u59cb\u5316\u4f7f\u7528\u65b9\u5f0f\u53ef\u4ee5\u6709\u4e09\u79cd\uff1a<\/p>\n<ul>\n<li><code>var  s  Student<\/code>\uff1a\u5148\u58f0\u660e\u53d8\u91cf\uff0c\u53d8\u91cf\u7684\u5c5e\u6027\u503c\u4e3a\u9ed8\u8ba4\u503c\uff0c\u7136\u540e\u518d\u5bf9\u5c5e\u6027\u8d4b\u503c\u3002<\/li>\n<li><code>s := Student {\"coderbee\",  28}<\/code>\uff1a\u6309\u7167\u58f0\u660e\u7684\u987a\u5e8f\u63d0\u4f9b\u5c5e\u6027\u7684\u521d\u59cb\u503c\u3002<\/li>\n<li><code>s := Student {name:\"coderbee\",  age:28}<\/code>\uff1a\u6309\u7167<code>field:value<\/code>\u7684\u5f62\u5f0f\u521d\u59cb\u5316\u5c5e\u6027\u503c\uff0c\u4efb\u610f\u987a\u5e8f\u3002<\/li>\n<\/ul>\n<h3>\u533f\u540d\u5b57\u6bb5<\/h3>\n<p>\u5982\u679c\u7701\u7565\u5b57\u6bb5\u7684\u540d\u5b57\uff0c\u53ef\u4ee5\u521b\u5efa\u533f\u540d\u5b57\u6bb5\uff08\u9ed8\u8ba4\u5b57\u6bb5\u540d\u662f\u7c7b\u578b\u7684\u540d\u5b57\uff0c\u6240\u4ee5\u4e00\u4e2astruct\u91cc\u9762\u4e0d\u80fd\u5b9a\u4e49\u4e24\u4e2a\u76f8\u540c\u7c7b\u578b\u7684\u533f\u540d\u5b57\u6bb5\uff09\u3002<\/p>\n<p>\u5f53\u533f\u540d\u5b57\u6bb5\u662f\u4e00\u4e2astruct\u7684\u65f6\u5019\uff0c\u8fd9\u4e2astruct\u6240\u62e5\u6709\u7684\u5168\u90e8\u5b57\u6bb5\u90fd\u88ab\u9690\u5f0f\u5730\u5f15\u5165\u5f53\u524d\u5b9a\u4e49\u7684\u8fd9\u4e2astruct\u3002\u5916\u56f4\u7684struct\u53ef\u4ee5\u50cf\u8bbf\u95ee\u81ea\u5df1\u7684\u5c5e\u6027\u90a3\u6837\u8bbf\u95ee\u533f\u540dstruct\u7684\u5c5e\u6027\u3002<\/p>\n<p>\u5982\u679c\u5185\u5c42struct\u4e0e\u5916\u5c42struct\u5177\u6709\u540c\u540d\u7684\u5b57\u6bb5\uff0c\u90a3\u4e48\u6700\u5916\u5c42\u7684\u4f18\u5148\u8bbf\u95ee\uff0c\u5bf9\u4e8e\u5185\u5c42\u5b57\u6bb5\u7684\u8bbf\u95ee\u53ef\u4ee5\u901a\u8fc7\u5185\u5c42struct\u7684\u5b57\u6bb5\u540d\u6765\u8bbf\u95ee\u3002<\/p>\n<pre><code>\npackage main\n\nimport \"fmt\"\n\ntype Human struct {\n    name   string\n    age    int\n    weight int\n}\n\ntype Student struct {\n    Human\n    spciality string\n    weight int\n}\n\nfunc main() {\n    mark := Student{Human{\"mark\", 25, 120}, \"computer science\", 125}\n    fmt.Printf(\"mark: %v\\n\", mark)\n    fmt.Printf(\"mark's name: %v\\n\", mark.name)\n    mark.weight = 130\n    fmt.Printf(\"out weight:%d, inner weight:%d, default weight:%d\\n\", mark.weight, mark.Human.weight, mark.weight)\n}\n<\/code><\/pre>\n<h3>\u65b9\u6cd5<\/h3>\n<p>\u65b9\u6cd5\u5c31\u662f\u6709\u63a5\u6536\u8005\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u5728\u4efb\u610f\u7c7b\u578b\u4e0a\u5b9a\u4e49\u65b9\u6cd5\uff08\u9664\u4e86\u975e\u672c\u5730\u7c7b\u578b\uff08\u5b9a\u4e49\u5728\u5176\u4ed6\u5305\u7684\uff09\uff0c\u5305\u62ec\u5185\u5efa\u7c7b\u578b\uff09\u3002<\/p>\n<p>\u63a5\u53e3\u5b9a\u4e49\u4e3a\u4e00\u4e2a\u65b9\u6cd5\u7684\u96c6\u5408\uff0c\u65b9\u6cd5\u5305\u542b\u5b9e\u9645\u4ee3\u7801\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u4e00\u4e2a\u63a5\u53e3\u662f\u5b9a\u4e49\uff0c\u800c\u65b9\u6cd5\u662f\u5b9e\u73b0\u3002\u56e0\u6b64\uff0c\u63a5\u6536\u8005\u4e0d\u80fd\u5b9a\u4e49\u4e3a\u63a5\u53e3\u7c7b\u578b\uff0c\u8fd9\u6837\u505a\u4f1a\u5f15\u8d77<code>invalid receiver type<\/code>\u7684\u7f16\u8bd1\u5668\u9519\u8bef\u3002\u6765\u81ea\u8bed\u8a00\u8bf4\u660e\u4e66\uff1a<br \/>\n\u63a5\u6536\u8005\u7c7b\u578b\u5fc5\u987b\u662f<code>T<\/code>\u6216<code>*T<\/code>\uff0c\u8fd9\u91cc\u7684<code>T<\/code>\u662f\u7c7b\u578b\u540d\u3002<code>T<\/code>\u53eb\u505a\u63a5\u6536\u8005\u57fa\u7840\u7c7b\u578b\u6216\u7b80\u79f0\u57fa\u7840\u7c7b\u578b\u3002\u57fa\u7840\u7c7b\u578b\u4e00\u5b9a\u4e0d\u80fd\u662f\u6307\u9488\u6216\u63a5\u53e3\u7c7b\u578b\uff0c\u5e76\u4e14\u5b9a\u4e49\u5728\u4e0e\u65b9\u6cd5\u76f8\u540c\u7684\u5305\u4e2d\u3002<\/p>\n<p>\u7ed9\u7c7b\u578b\u6dfb\u52a0\u65b9\u6cd5\u6709\u51e0\u79cd\u9014\u5f84\uff1a<\/p>\n<ul>\n<li>\u51fd\u6570\u8c03\u7528\uff1a <code>func doSomething(s * Student, age int) { \/* ... *\/ }<\/code><\/li>\n<li>\u65b9\u6cd5\u8c03\u7528\uff0c\u7c7b\u578b\u6307\u9488\u4e0a\u6dfb\u52a0\uff1a <code>func (s * Student)doSomething(age int) { \/* ... *\/ }<\/code><\/li>\n<li>\u65b9\u6cd5\u8c03\u7528\uff0c\u7c7b\u578b\u503c\u4e0a\u6dfb\u52a0\uff1a <code>func (s Student)doSomething(age int) { \/* ... *\/ }<\/code><\/li>\n<\/ul>\n<p>\u6307\u9488\u7c7b\u578b\u4e0a\u6dfb\u52a0\u548c\u7c7b\u578b\u503c\u4e0a\u6dfb\u52a0\u7684\u533a\u522b\u5728\u4e8e\uff1a \u6307\u9488\u4f5c\u4e3aReceiver\u4f1a\u5bf9\u5b9e\u4f8b\u5bf9\u8c61\u7684\u5185\u5bb9\u53d1\u751f\u64cd\u4f5c\uff0c\u800c\u666e\u901a\u7c7b\u578b\u4f5c\u4e3aReceiver\u4ec5\u4ec5\u662f\u4ee5\u526f\u672c\u4f5c\u4e3a\u64cd\u4f5c\u5bf9\u8c61\uff0c\u5e76\u4e0d\u5bf9\u539f\u5b9e\u4f8b\u5bf9\u8c61\u53d1\u751f\u64cd\u4f5c\u3002<\/p>\n<p>\u5982\u679c<code>x<\/code>\u53ef\u83b7\u53d6\u5730\u5740\uff0c\u5e76\u4e14<code>&amp;x<\/code>\u7684\u65b9\u6cd5\u4e2d\u5305\u542b\u4e86m\uff0c<code>x.m()<\/code>\u662f<code>(&amp;x).m()<\/code>\u66f4\u77ed\u7684\u5199\u6cd5\u3002<\/p>\n<p>\u5982\u679c\u4e00\u4e2amethod\u7684receiver\u662f<code>*T<\/code>\uff0c\u4f60\u53ef\u4ee5\u5728\u4e00\u4e2a<code>T<\/code>\u7c7b\u578b\u7684\u5b9e\u4f8b\u53d8\u91cfV\u4e0a\u9762\u8c03\u7528\u8fd9\u4e2amethod\uff0c\u800c\u4e0d\u9700\u8981<code>&amp;V<\/code>\u53bb\u8c03\u7528\u8fd9\u4e2amethod\u3002<br \/>\n\u5982\u679c\u4e00\u4e2amethod\u7684receiver\u662f<code>T<\/code>\uff0c\u4f60\u53ef\u4ee5\u5728\u4e00\u4e2a<code>*T<\/code>\u7c7b\u578b\u7684\u53d8\u91cfP\u4e0a\u9762\u8c03\u7528\u8fd9\u4e2amethod\uff0c\u800c\u4e0d\u9700\u8981<code>*P<\/code>\u53bb\u8c03\u7528\u8fd9\u4e2amethod\u3002<\/p>\n<h2>\u63a5\u53e3 interface<\/h2>\n<p>\u6bcf\u4e2a\u7c7b\u578b\u90fd\u6709\u63a5\u53e3\uff0c\u610f\u5473\u7740\u5bf9\u90a3\u4e2a\u7c7b\u578b\u5b9a\u4e49\u4e86\u65b9\u6cd5\u96c6\u5408\u3002interface\u7c7b\u578b\u5b9a\u4e49\u4e86\u4e00\u7ec4\u65b9\u6cd5\uff0c\u5982\u679c\u67d0\u4e2a\u5bf9\u8c61\u5b9e\u73b0\u4e86\u67d0\u4e2a\u63a5\u53e3\u7684\u6240\u6709\u65b9\u6cd5\uff0c\u5219\u6b64\u5bf9\u8c61\u5c31\u5b9e\u73b0\u4e86\u6b64\u63a5\u53e3\u3002<\/p>\n<h3>\u5b9a\u4e49<\/h3>\n<pre><code>\ntype I interface {\n    Get() int\n    Put(int)\n}\n\ntype S struct { i int }\nfunc (p *S) Get() int { return p.i }\nfunc (p *S) Put(v int) { p.i = v }\n<\/code><\/pre>\n<p>\u5bf9\u4e8e\u63a5\u53e3I\uff0cS\u662f\u5408\u6cd5\u7684\u5b9e\u73b0\uff0c\u56e0\u4e3a\u5b83\u5b9a\u4e49\u4e86I\u6240\u9700\u7684\u4e24\u4e2a\u65b9\u6cd5\u3002<\/p>\n<p>\u6bcf\u4e2a\u7c7b\u578b\u90fd\u80fd\u5339\u914d\u5230\u7a7a\u63a5\u53e3\uff1a <code>interface{}<\/code>\u3002 \u7a7ainterface\u5728\u6211\u4eec\u9700\u8981\u5b58\u50a8\u4efb\u610f\u7c7b\u578b\u7684\u6570\u503c\u7684\u65f6\u5019\u76f8\u5f53\u6709\u7528\uff0c\u56e0\u4e3a\u5b83\u53ef\u4ee5\u5b58\u50a8\u4efb\u610f\u7c7b\u578b\u7684\u6570\u503c\u3002\u5b83\u6709\u70b9\u7c7b\u4f3c\u4e8eC\u8bed\u8a00\u7684<code>void*<\/code>\u7c7b\u578b\u3002<\/p>\n<p>\u65e0\u9700\u660e\u786e\u4e00\u4e2a\u7c7b\u578b\u662f\u5426\u5b9e\u73b0\u4e86\u4e00\u4e2a\u63a5\u53e3\u610f\u5473\u7740Go\u5b9e\u73b0\u4e86<code>duck typing<\/code>\u7684\u6a21\u5f0f\u3002\u8fd9\u4e0d\u662f\u7eaf\u7cb9\u7684<code>duck typing<\/code>\uff0c\u56e0\u4e3a\u5982\u679c\u53ef\u80fd\u7684\u8bddGo\u7f16\u8bd1\u5668\u5c06\u5bf9\u7c7b\u578b\u662f\u5426\u5b9e\u73b0\u4e86\u63a5\u53e3\u8fdb\u884c\u9759\u6001\u68c0\u67e5\u3002<\/p>\n<h3>\u7c7b\u578b\u5224\u65ad<\/h3>\n<p>\u65b9\u6cd5\u4e00\uff1a<\/p>\n<pre><code>\nfunc  getType(p  interface{}) string {\nswitch p.(type) {\n    case int:  return \"int\"\n    case string:  return \"string\"\n    case Person:  return \"Person\"\n    default:    return \"unknow type\"\n}\n}\n<\/code><\/pre>\n<p>\u5728<code>switch<\/code>\u4e4b\u5916\u4f7f\u7528<code>(type)<\/code>\u662f\u975e\u6cd5\u7684\u3002<\/p>\n<p>\u65b9\u6cd5\u4e8c\uff1a<br \/>\n\u53e6\u4e00\u79cd\u5224\u65ad\u4e00\u4e2a\u63a5\u53e3\u7c7b\u578b\u662f\u5426\u5b9e\u73b0\u4e86\u67d0\u4e2a\u7279\u5b9a\u63a5\u53e3\u7684\u65b9\u6cd5\uff1a<\/p>\n<pre><code>\nfunc runtimeType(any interface{}) {\n   if _, ok := any.(I); ok {\n       println(\"type is I .\")\n   } else if  _, ok := any.(int); ok {\n       println(\"type is int .\")\n   }\n}\n<\/code><\/pre>\n<p><code>.(I)<\/code>\u662f\u65ad\u8a00\u7c7b\u578b\uff0c\u7528\u4e8e\u8f6c\u6362any\u5230I\u7c7b\u578b\u7684\u63a5\u53e3\u3002<\/p>\n<h3>\u7ee7\u627f<\/h3>\n<p>Go\u4e0d\u652f\u6301\u7ee7\u627f\uff0c\u9f13\u52b1\u4f7f\u7528\u7ec4\u5408\u548c\u59d4\u6d3e\u3002<\/p>\n<pre><code>\ntype Engine interface {\n  Start()\n  Stop()\n}\n\ntype Car struct {\n  Engine\n}\n<\/code><\/pre>\n<p>\u5b9a\u4e49Car\u7684\u65f6\u5019\uff0cEngine\u662f\u4e00\u4e2a\u533f\u540d\u6210\u5458\uff0c\u8fd9\u662f\u4e00\u4e2a\u53ea\u80fd\u88ab\u5176\u7c7b\u578b\u8bc6\u522b\u7684\u6210\u5458\u3002\u533f\u540d\u6210\u5458\u548c\u5176\u4ed6\u7684\u6210\u5458\u4e00\u6837\uff0c\u5e76\u6709\u7740\u548c\u7c7b\u578b\u4e00\u6837\u7684\u540d\u5b57\u3002<\/p>\n<p>\u5982\u679c\u4e00\u4e2a\u7c7b\u578b\u5b9a\u4e49\u4e86\u4e00\u4e2a\u65b9\u6cd5\uff0c\u5c31\u4f7f\u7528\u5b83\uff1b\u5982\u679c\u4e0d\u662f\uff0c\u5c31\u4f7f\u7528\u533f\u540d\u6210\u5458\u5b9a\u4e49\u7684\u65b9\u6cd5\u3002\u5982\u679c\u4e24\u4e2a\u533f\u540d\u6210\u5458\u90fd\u63d0\u4f9b\u4e00\u4e2a\u65b9\u6cd5\uff0c\u7f16\u8bd1\u5668\u4f1a\u62a5\u9519\uff0c\u4f46\u53ea\u5728\u8be5\u65b9\u6cd5\u88ab\u8c03\u7528\u7684\u60c5\u51b5\u4e0b\u3002<\/p>\n<p>\u8fd9\u79cd\u7ec4\u5408\u662f\u901a\u8fc7\u59d4\u6d3e\u6765\u5b9e\u73b0\u7684\uff0c\u800c\u4e0d\u662f\u7ee7\u627f\u3002\u4e00\u65e6\u533f\u540d\u6210\u5458\u7684\u65b9\u6cd5\u88ab\u8c03\u7528\uff0c\u63a7\u5236\u6d41\u5c31\u88ab\u59d4\u6258\u7ed9\u4e86\u8be5\u65b9\u6cd5\u3002<\/p>\n<pre><code>\ntype Base struct {}\nfunc (Base) Magic() { fmt.Print(\"base magic\") }\nfunc (self Base) MoreMagic() {\n  self.Magic()\n  self.Magic()\n}\n\ntype Foo struct {\n  Base\n}\nfunc (Foo) Magic() { fmt.Print(\"foo magic\") }\n\n\/\/ \u5c06\u5f97\u5230\uff1a\nf := new(Foo)\nf.Magic() \/\/=> foo magic\nf.MoreMagic() \/\/=> base magic base magic\n<\/code><\/pre>\n<p><strong>\u8981\u6ce8\u610f\u4e24\u79cd\u7ee7\u627f\u7684\u4e0d\u540c\u4e4b\u5904<\/strong><br \/>\n<code>type NewStudent Student<\/code>                  \/\/ \u4e0d\u4f1a\u7ee7\u627f Student \u7684\u65b9\u6cd5<br \/>\n<code>type SubStudent struct { Student }<\/code>     \/\/  \u4f1a\u7ee7\u627f Student \u7684\u65b9\u6cd5<\/p>\n<h2>\u5e76\u53d1<\/h2>\n<p>\u5e76\u884c\u662f\u5173\u4e8e\u6027\u80fd\u7684\uff1b\u5e76\u53d1\u662f\u5173\u4e8e\u7a0b\u5e8f\u8bbe\u8ba1\u7684\u3002<\/p>\n<h3>goroutine<\/h3>\n<p>goroutine\u662f\u4e00\u4e2a\u666e\u901a\u7684\u51fd\u6570\uff0c\u53ea\u662f\u9700\u8981\u4f7f\u7528\u4fdd\u7559\u5b57go\u4f5c\u4e3a\u5f00\u5934\u3002<br \/>\ngoroutine\u6709\u7b80\u5355\u7684\u6a21\u578b\uff1a\u5b83\u662f\u4e0e\u5176\u4ed6goroutine\u5e76\u884c\u6267\u884c\u7684\uff0c\u6709\u7740\u76f8\u540c\u5730\u5740\u7a7a\u95f4\u7684\u51fd\u6570\u3002\u662f\u8f7b\u91cf\u7684\uff0c\u4ec5\u6bd4\u5206\u914d\u6808\u7a7a\u95f4\u591a\u4e00\u70b9\u70b9\u6d88\u8017\uff0c\u5e76\u4e14\u968f\u7740\u9700\u8981\u5728\u5806\u7a7a\u95f4\u4e0a\u5206\u914d\uff08\u548c\u91ca\u653e\uff09\u3002<\/p>\n<p>\u867d\u7136goroutine\u662f\u5e76\u53d1\u6267\u884c\u7684\uff0c\u4f46\u662f\u5b83\u4eec\u5e76\u4e0d\u662f\u5e76\u884c\u6267\u884c\u7684\u3002\u5982\u679c\u4e0d\u544a\u8bc9Go\u989d\u5916\u7684\u4e1c\u897f\uff0c\u540c\u4e00\u65f6\u523b\u53ea\u4f1a\u6709\u4e00\u4e2agoroutine\u6267\u884c\u3002\u5229\u7528<code>runtime.GOMAXPROCS(n)<\/code>\u53ef\u4ee5\u8bbe\u7f6egoroutine\u5e76\u884c\u6267\u884c\u7684\u6570\u91cf\u3002\u6765\u81ea\u6587\u6863\uff1a<code>GOMAXPROCS<\/code>\u8bbe\u7f6e\u4e86\u540c\u65f6\u8fd0\u884c\u7684CPU\u7684\u6700\u5927\u6570\u91cf\uff0c\u5e76\u8fd4\u56de\u4e4b\u524d\u7684\u8bbe\u7f6e\u3002\u5982\u679c<code>n&lt;1<\/code>\uff0c\u4e0d\u4f1a\u6539\u53d8\u5f53\u524d\u8bbe\u7f6e\u3002\u5f53\u8c03\u5ea6\u5f97\u5230\u6539\u8fdb\u540e\uff0c\u8fd9\u5c06\u88ab\u79fb\u9664\u3002<\/p>\n<h3>runtime\u4e0egoroutine<\/h3>\n<p>runtime\u5305\u6709\u51e0\u4e2a\u5904\u7406goroutine\u7684\u51fd\u6570\uff1a<\/p>\n<ul>\n<li><code>Goexit<\/code>\uff1a\u9000\u51fa\u5f53\u524d\u6267\u884c\u7684goroutine\uff0c\u4f46\u662f<code>defer<\/code>\u51fd\u6570\u8fd8\u662f\u4f1a\u7ee7\u7eed\u8c03\u7528\u3002<\/li>\n<li><code>Gosched<\/code>\uff1a\u8ba9\u51fa\u5f53\u524dgoroutine\u7684\u6267\u884c\u6743\u9650\uff0c\u6389\u8d4c\u6c14\u5b89\u6392\u5176\u4ed6\u7b49\u5f85\u4e2d\u7684\u4efb\u52a1\u8fd0\u884c\uff0c\u5e76\u5728\u4e0b\u6b21\u67d0\u4e2a\u65f6\u5019\u4ece\u8be5\u4f4d\u7f6e\u6062\u590d\u6267\u884c\u3002\uff08\u76f8\u5f53\u4e8eJava\u7684<code>Thread.yield()<\/code>\uff09<\/li>\n<li><code>NumCPU<\/code>\uff1a\u8fd4\u56deCPU\u6838\u6570\u91cf\u3002<\/li>\n<li><code>NumGoroutine<\/code>\uff1a\u8fd4\u56de\u6b63\u5728\u6267\u884c\u548c\u6392\u961f\u7684\u4efb\u52a1\u603b\u6570\u3002<\/li>\n<li><code>GOMAXPROCS<\/code>\uff1a\u7528\u6765\u8bbe\u7f6e\u53ef\u4ee5\u8fd0\u884c\u7684CPU\u6838\u6570\u3002<\/li>\n<\/ul>\n<h3>channel<\/h3>\n<p>channel\u53ef\u4ee5\u4e0eUnix shell\u4e2d\u7684\u53cc\u5411\u7ba1\u9053\u505a\u7c7b\u6bd4\uff1a\u53ef\u4ee5\u901a\u8fc7\u5b83\u53d1\u9001\u6216\u8005\u63a5\u6536\u503c\uff0c\u8fd9\u4e9b\u503c\u53ea\u80fd\u662f\u7279\u5b9a\u7684\u7c7b\u578b\uff1achannel\u7c7b\u578b\u3002\u5b9a\u4e49\u4e00\u4e2achannel\u65f6\uff0c\u4e5f\u9700\u8981\u5b9a\u4e49\u53d1\u9001\u5230channel\u7684\u503c\u7684\u7c7b\u578b\u3002<\/p>\n<p>\u5fc5\u987b\u4f7f\u7528<code>make<\/code>\u521b\u5efachannel\uff0c\u5982\u679c\u521b\u5efa\u65f6\u4e0d\u6307\u5b9a\u5927\u5c0f\uff0c\u5c06\u521b\u5efa\u65e0\u7f13\u51b2\u7684channel\u3002\u65e0\u7f13\u51b2\u610f\u5473\u7740\uff1a\u8bfb\u53d6\u65f6\u5c06\u88ab\u963b\u585e\uff0c\u76f4\u5230\u6709\u6570\u636e\u53ef\u63a5\u6536\uff1b\u53d1\u9001\u4e5f\u5c06\u88ab\u963b\u585e\uff0c\u76f4\u5230\u6570\u636e\u88ab\u8bfb\u51fa\u3002\u65e0\u7f13\u51b2channel\u53ef\u5728\u591a\u4e2agoroutine\u4e4b\u95f4\u540c\u6b65\u3002<br \/>\n<a href=\"\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/go-channel.png\"><img loading=\"lazy\" decoding=\"async\" src=\"\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/go-channel-300x93.png\" alt=\"go-channel\" width=\"300\" height=\"93\" class=\"alignnone size-medium wp-image-333\" srcset=\"https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/go-channel-300x93.png 300w, https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/go-channel-624x194.png 624w, https:\/\/coderbee.net\/wp-content\/uploads\/2013\/07\/go-channel.png 667w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p>\u521b\u5efa\uff1a <code>ci := make(chan int);  ci := make(chan int, 4)<\/code>  \/\/        4\u662fchannel\u7684\u7f13\u51b2\u5927\u5c0f\u3002<br \/>\n\u53d1\u9001\u5230channel\uff1a <code>ci &lt;- 1<\/code><br \/>\n\u4ecechannel\u63a5\u6536\uff1a <code>i := &lt;- ci<\/code><\/p>\n<h4>range\u548cclose<\/h4>\n<p><code>for i := range c<\/code>\u7684\u5f62\u5f0f\u80fd\u591f\u4e0d\u65ad\u5730\u4ecechannel c\u8bfb\u53d6\u6570\u636e\uff0c\u76f4\u5230c\u88ab\u663e\u5f0f\u5173\u95ed\u3002<\/p>\n<p>\u5173\u95edchannel\u4e4b\u540e\u5c31\u65e0\u6cd5\u518d\u53d1\u9001\u4efb\u4f55\u6570\u636e\u4e86\uff0c\u5728\u6d88\u8d39\u65b9\u53ef\u4ee5\u901a\u8fc7\u8bed\u6cd5<code>v, ok := &lt;-ch<\/code>\u6d4b\u8bd5channel\u662f\u5426\u88ab\u5173\u95ed\u3002\u5982\u679c<code>ok<\/code>\u8fd4\u56de<code>false<\/code>\uff0c\u90a3\u4e48\u8bf4\u660echannel\u5df2\u7ecf\u6ca1\u6709\u4efb\u4f55\u6570\u636e\u5e76\u4e14\u5df2\u7ecf\u88ab\u5173\u95ed\u3002<\/p>\n<pre><code>\u8bb0\u4f4f\u5e94\u8be5\u5728\u751f\u4ea7\u8005\u7684\u5730\u65b9\u5173\u95edchannel\uff0c\u800c\u4e0d\u662f\u6d88\u8d39\u7684\u5730\u65b9\u53bb\u5173\u95ed\u5b83\uff0c\u8fd9\u6837\u5bb9\u6613\u5f15\u8d77panic\n\n\u53e6\u5916\u8bb0\u4f4f\u4e00\u70b9\u7684\u5c31\u662fchannel\u4e0d\u50cf\u6587\u4ef6\u4e4b\u7c7b\u7684\uff0c\u4e0d\u9700\u8981\u7ecf\u5e38\u53bb\u5173\u95ed\uff0c\u53ea\u6709\u5f53\u4f60\u786e\u5b9e\u6ca1\u6709\u4efb\u4f55\u53d1\u9001\u6570\u636e\u4e86\uff0c\u6216\u8005\u4f60\u60f3\u663e\u5f0f\u7684\u7ed3\u675frange\u5faa\u73af\u4e4b\u7c7b\u7684\n<\/code><\/pre>\n<h4>select<\/h4>\n<p>select\u53ef\u4ee5\u76d1\u542c\u591a\u4e2achannel\u4e0a\u7684\u6570\u636e\u6d41\u52a8\u3002<\/p>\n<p>select\u9ed8\u8ba4\u662f\u963b\u585e\u7684\uff0c\u53ea\u6709\u5f53\u76d1\u542c\u7684channel\u4e2d\u6709\u53d1\u9001\u6216\u63a5\u6536\u53ef\u4ee5\u8fdb\u884c\u65f6\u624d\u4f1a\u8fd0\u884c\uff0c\u5f53\u591a\u4e2achannel\u90fd\u51c6\u5907\u597d\u7684\u65f6\u5019\uff0cselect\u662f\u968f\u673a\u7684\u9009\u62e9\u4e00\u4e2a\u6267\u884c\u7684\u3002<\/p>\n<p>\u5728select\u91cc\u9762\u8fd8\u6709default\u8bed\u6cd5\uff0cselect\u5176\u5b9e\u5c31\u662f\u7c7b\u4f3cswitch\u7684\u529f\u80fd\uff0cdefault\u5c31\u662f\u5f53\u76d1\u542c\u7684channel\u90fd\u6ca1\u6709\u51c6\u5907\u597d\u7684\u65f6\u5019\uff0c\u9ed8\u8ba4\u6267\u884c\u7684\uff08select\u4e0d\u518d\u963b\u585e\u7b49\u5f85channel\uff09\u3002<\/p>\n<h4>\u8d85\u65f6<\/h4>\n<p>\u53ef\u4ee5\u5229\u7528select\u6765\u8bbe\u7f6e\u8d85\u65f6\uff0c\u901a\u8fc7\u5982\u4e0b\u7684\u65b9\u5f0f\u5b9e\u73b0\uff1a<\/p>\n<pre><code>\nfunc main() {\n    c := make(chan int)\n    o := make(chan bool)\n    go func() {\n        for {\n            select {\n                case v := <- c:\n                    println(v)\n                case <- time.After(5 * time.Second):\n                    println(\"timeout\")\n                    o <- true\n                    break\n            }\n        }\n    }()\n    <- o\n}\n<\/code><\/pre>\n<hr\/>\n<p>\u6b22\u8fce\u5173\u6ce8\u6211\u7684\u5fae\u4fe1\u516c\u4f17\u53f7: <strong>coderbee\u7b14\u8bb0<\/strong>\uff0c\u53ef\u4ee5\u66f4\u53ca\u65f6\u56de\u590d\u4f60\u7684\u8ba8\u8bba\u3002<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" width=\"258\" height=\"258\" src=\"https:\/\/coderbee.net\/wp-content\/uploads\/2019\/01\/coderbee-note.jpg\" class=\"alignnone size-full wp-image-1707\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u51fd\u6570 \u5b9a\u4e49\uff1a<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45],"tags":[232],"_links":{"self":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/327"}],"collection":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/comments?post=327"}],"version-history":[{"count":5,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/327\/revisions"}],"predecessor-version":[{"id":336,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/posts\/327\/revisions\/336"}],"wp:attachment":[{"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/media?parent=327"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/categories?post=327"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/coderbee.net\/index.php\/wp-json\/wp\/v2\/tags?post=327"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}