{"id":1235,"date":"2022-11-22T20:02:03","date_gmt":"2022-11-22T12:02:03","guid":{"rendered":"https:\/\/fdream.net\/blog\/?p=1235"},"modified":"2022-11-22T20:02:03","modified_gmt":"2022-11-22T12:02:03","slug":"go%e6%8c%87%e5%8d%97%e7%bb%83%e4%b9%a01-%e5%be%aa%e7%8e%af%e4%b8%8e%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/fdream.net\/blog\/article\/1235","title":{"rendered":"Go\u6307\u5357\u7ec3\u4e601-\u5faa\u73af\u4e0e\u51fd\u6570"},"content":{"rendered":"\n<p><a rel=\"noreferrer noopener\" href=\"https:\/\/go.dev\/tour\/list\" target=\"_blank\">A Tour of Go<\/a>\u8fd9\u4e2a\u6559\u7a0b\uff08<a href=\"https:\/\/tour.go-zh.org\/list\" target=\"_blank\" rel=\"noreferrer noopener\">\u4e2d\u6587\u7248<\/a>\uff09\u771f\u662f\u505a\u7684\u592a\u597d\u4e86\uff0c\u5b66\u4e60\u548c\u7ec3\u4e60Go\u7684\u57fa\u7840\u8fd8\u662f\u5f88\u4e0d\u9519\u7684\u3002\u628a\u4e0a\u9762\u7684\u7ec3\u4e60\u90fd\u505a\u4e86\uff0c\u6765\u505a\u4e2a\u8bb0\u5f55\u3002\u8fd9\u4e2a\u7ec3\u4e60\u662f\u63a7\u5236\u4e0e\u5faa\u73af\u91cc\u9762\u7684\uff0c<a rel=\"noreferrer noopener\" href=\"https:\/\/go.dev\/tour\/flowcontrol\/8\" target=\"_blank\">\u539f\u9898<\/a>\u5982\u4e0b\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>\u4e3a\u4e86\u7ec3\u4e60\u51fd\u6570\u4e0e\u5faa\u73af\uff0c\u6211\u4eec\u6765\u5b9e\u73b0\u4e00\u4e2a\u5e73\u65b9\u6839\u51fd\u6570\uff1a\u7528\u725b\u987f\u6cd5\u5b9e\u73b0\u5e73\u65b9\u6839\u51fd\u6570\u3002<\/p>\n\n\n\n<p>\u8ba1\u7b97\u673a\u901a\u5e38\u4f7f\u7528\u5faa\u73af\u6765\u8ba1\u7b97 x \u7684\u5e73\u65b9\u6839\u3002\u4ece\u67d0\u4e2a\u731c\u6d4b\u7684\u503c z \u5f00\u59cb\uff0c\u6211\u4eec\u53ef\u4ee5\u6839\u636e z\u00b2 \u4e0e x \u7684\u8fd1\u4f3c\u5ea6\u6765\u8c03\u6574 z\uff0c\u4ea7\u751f\u4e00\u4e2a\u66f4\u597d\u7684\u731c\u6d4b\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>z -= (z*z - x) \/ (2*z)<\/code><\/pre>\n\n\n\n<p>\u91cd\u590d\u8c03\u6574\u7684\u8fc7\u7a0b\uff0c\u731c\u6d4b\u7684\u7ed3\u679c\u4f1a\u8d8a\u6765\u8d8a\u7cbe\u786e\uff0c\u5f97\u5230\u7684\u7b54\u6848\u4e5f\u4f1a\u5c3d\u53ef\u80fd\u63a5\u8fd1\u5b9e\u9645\u7684\u5e73\u65b9\u6839\u3002<\/p>\n\n\n\n<p>\u5728\u63d0\u4f9b\u7684&nbsp;<code>func Sqrt<\/code>&nbsp;\u4e2d\u5b9e\u73b0\u5b83\u3002\u65e0\u8bba\u8f93\u5165\u662f\u4ec0\u4e48\uff0c\u5bf9 z \u7684\u4e00\u4e2a\u6070\u5f53\u7684\u731c\u6d4b\u4e3a 1\u3002 \u8981\u5f00\u59cb\uff0c\u8bf7\u91cd\u590d\u8ba1\u7b97 10 \u6b21\u5e76\u968f\u4e4b\u6253\u5370\u6bcf\u6b21\u7684 z \u503c\u3002\u89c2\u5bdf\u5bf9\u4e8e\u4e0d\u540c\u7684\u503c x\uff081\u30012\u30013 &#8230;\uff09\uff0c \u4f60\u5f97\u5230\u7684\u7b54\u6848\u662f\u5982\u4f55\u903c\u8fd1\u7ed3\u679c\u7684\uff0c\u731c\u6d4b\u63d0\u5347\u7684\u901f\u5ea6\u6709\u591a\u5feb\u3002<\/p>\n\n\n\n<p>\u63d0\u793a\uff1a\u7528\u7c7b\u578b\u8f6c\u6362\u6216\u6d6e\u70b9\u6570\u8bed\u6cd5\u6765\u58f0\u660e\u5e76\u521d\u59cb\u5316\u4e00\u4e2a\u6d6e\u70b9\u6570\u503c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>z := 1.0\nz := float64(1)<\/code><\/pre>\n\n\n\n<p>\u7136\u540e\uff0c\u4fee\u6539\u5faa\u73af\u6761\u4ef6\uff0c\u4f7f\u5f97\u5f53\u503c\u505c\u6b62\u6539\u53d8\uff08\u6216\u6539\u53d8\u975e\u5e38\u5c0f\uff09\u7684\u65f6\u5019\u9000\u51fa\u5faa\u73af\u3002\u89c2\u5bdf\u8fed\u4ee3\u6b21\u6570\u5927\u4e8e\u8fd8\u662f\u5c0f\u4e8e 10\u3002 \u5c1d\u8bd5\u6539\u53d8 z \u7684\u521d\u59cb\u731c\u6d4b\uff0c\u5982 x \u6216 x\/2\u3002\u4f60\u7684\u51fd\u6570\u7ed3\u679c\u4e0e\u6807\u51c6\u5e93\u4e2d\u7684&nbsp;<a href=\"https:\/\/go-zh.org\/pkg\/math\/#Sqrt\" target=\"_blank\" rel=\"noreferrer noopener\">math.Sqrt<\/a>&nbsp;\u63a5\u8fd1\u5417\uff1f<\/p>\n\n\n\n<p>\uff08*\u6ce8\uff1a* \u5982\u679c\u4f60\u5bf9\u8be5\u7b97\u6cd5\u7684\u7ec6\u8282\u611f\u5174\u8da3\uff0c\u4e0a\u9762\u7684 z\u00b2 \u2212 x \u662f z\u00b2 \u5230\u5b83\u6240\u8981\u5230\u8fbe\u7684\u503c\uff08\u5373 x\uff09\u7684\u8ddd\u79bb\uff0c \u9664\u4ee5\u7684 2z \u4e3a z\u00b2 \u7684\u5bfc\u6570\uff0c\u6211\u4eec\u901a\u8fc7 z\u00b2 \u7684\u53d8\u5316\u901f\u5ea6\u6765\u6539\u53d8 z \u7684\u8c03\u6574\u91cf\u3002 \u8fd9\u79cd\u901a\u7528\u65b9\u6cd5\u53eb\u505a<a href=\"https:\/\/zh.wikipedia.org\/wiki\/%E7%89%9B%E9%A1%BF%E6%B3%95\" target=\"_blank\" rel=\"noreferrer noopener\">\u725b\u987f\u6cd5<\/a>\u3002 \u5b83\u5bf9\u5f88\u591a\u51fd\u6570\uff0c\u7279\u522b\u662f\u5e73\u65b9\u6839\u800c\u8a00\u975e\u5e38\u6709\u6548\u3002\uff09<\/p>\n<\/blockquote>\n\n\n\n<p>\u5148\u5b8c\u6210\u7b2c\u4e00\u4e2a\u7ec3\u4e60\uff0c\u5faa\u73af\u5341\u6b21\uff0c\u5e76\u4e14\u6bcf\u6b21\u6253\u5370\u7ed3\u679c\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>package main\n\nimport (\n\t\"fmt\"\n)\n\nfunc Sqrt(x float64) float64 {\n\tz := x  \/\/ \u521d\u59cb\u5316\u4e3a\u6d6e\u70b9\u6570\n\tfor i := 0; i &lt; 10; i++ {\n\t\tz -= (z*z -x) \/ (2*z)\n\t\tfmt.Println(i,z)  \/\/ \u6253\u5370\u6bcf\u6b21\u7684\u4e2d\u95f4\u7ed3\u679c\n\t}\n\treturn z \/\/ \u8fd4\u56de\u6700\u7ec8\u7ed3\u679c\n}\n\nfunc main() {\n\tfmt.Println(Sqrt(2))\n}<\/code><\/pre>\n\n\n\n<p>\u53ef\u4ee5\u770b\u5230\u57fa\u672c\u4e0a\u7b2c\u4e94\u6b21\u5c31\u6bd4\u8f83\u7a33\u5b9a\u4e86\u3002<\/p>\n\n\n\n<p>\u518d\u6765\u6839\u636e\u9898\u76ee\u4f18\u5316\u4e00\u4e0b\uff0c\u5b8c\u6210\u7b2c\u4e8c\u4e2a\u7ec3\u4e60\uff0c\u5f53\u53d8\u5316\u6781\u5c0f\u6216\u8005\u672a\u53d8\u5316\u65f6\u505c\u6b62\u5faa\u73af\u8ba1\u7b97\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>package main\n\nimport (\n\t\"fmt\"\n\t\"math\"\n)\n\nconst delta = 1e-9\n\nfunc Sqrt(x float64) float64 {\n\tz := x\n\tlast := 0.0\t\/\/ \u4e0a\u6b21\u8ba1\u7b97\u7ed3\u679c\n\ti := 0 \/\/ \u5faa\u73af\u6b21\u6570\n\t\n\t\/\/ \u4e0e\u4e0a\u6b21\u8ba1\u7b97\u7ed3\u679c\u5dee\u8ddd\u5927\u4e8e1e-9\u65f6\u7ee7\u7eed\u8ba1\u7b97\uff0c\u5426\u5219\u8fd4\u56de\u7ed3\u679c\n\tfor math.Abs(z - last) > delta {\n\t\tlast, z = z, z - (z*z -x) \/ (2*z)\n\t\ti++\n\t\tfmt.Println(i,z)\n\t}\n\treturn z\n}\n\nfunc main() {\n\tfmt.Println(Sqrt(2))\n}<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>A Tour of Go\u8fd9\u4e2a\u6559\u7a0b\uff08\u4e2d\u6587\u7248\uff09\u771f\u662f\u505a\u7684\u592a\u597d\u4e86\uff0c\u5b66\u4e60\u548c\u7ec3\u4e60Go\u7684\u57fa\u7840\u8fd8\u662f\u5f88\u4e0d\u9519\u7684\u3002\u628a\u4e0a\u9762\u7684\u7ec3\u4e60\u90fd\u505a\u4e86\uff0c\u6765\u505a\u4e2a\u8bb0\u5f55\u3002\u8fd9\u4e2a\u7ec3\u4e60\u662f\u63a7\u5236\u4e0e\u5faa\u73af\u91cc\u9762\u7684\uff0c\u539f\u9898\u5982\u4e0b\uff1a \u5148\u5b8c\u6210\u7b2c\u4e00\u4e2a\u7ec3\u4e60\uff0c\u5faa\u73af\u5341\u6b21\uff0c\u5e76\u4e14\u6bcf\u6b21\u6253\u5370\u7ed3\u679c\uff1a \u53ef\u4ee5\u770b\u5230\u57fa\u672c\u4e0a\u7b2c\u4e94\u6b21\u5c31\u6bd4\u8f83\u7a33\u5b9a\u4e86\u3002 \u518d\u6765\u6839\u636e\u9898\u76ee\u4f18\u5316\u4e00\u4e0b\uff0c\u5b8c\u6210\u7b2c\u4e8c\u4e2a\u7ec3\u4e60\uff0c\u5f53\u53d8\u5316\u6781\u5c0f\u6216\u8005\u672a\u53d8\u5316\u65f6\u505c\u6b62\u5faa\u73af\u8ba1\u7b97\uff1a<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[374],"class_list":["post-1235","post","type-post","status-publish","format-standard","hentry","category-coding","tag-go"],"views":369,"_links":{"self":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts\/1235","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/comments?post=1235"}],"version-history":[{"count":0,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/posts\/1235\/revisions"}],"wp:attachment":[{"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/media?parent=1235"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/categories?post=1235"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fdream.net\/blog\/wp-json\/wp\/v2\/tags?post=1235"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}