{"id":538,"date":"2018-02-23T23:39:05","date_gmt":"2018-02-23T15:39:05","guid":{"rendered":"http:\/\/60.205.208.74\/2018\/02\/23\/swift-%e5%b1%9e%e6%80%a7\/"},"modified":"2018-02-23T23:39:05","modified_gmt":"2018-02-23T15:39:05","slug":"swift-%e5%b1%9e%e6%80%a7","status":"publish","type":"post","link":"https:\/\/www.puzi7.net\/?p=538","title":{"rendered":"Swift \u5c5e\u6027"},"content":{"rendered":"<span itemprop=\"description\"><div class=\"article-body\">\n<div class=\"article-intro\" id=\"content\">\n<h1>Swift \u5c5e\u6027<\/h1>\n<p>Swift \u5c5e\u6027\u5c06\u503c\u8ddf\u7279\u5b9a\u7684\u7c7b\u3001\u7ed3\u6784\u6216\u679a\u4e3e\u5173\u8054\u3002<\/p>\n<p>\u5c5e\u6027\u53ef\u5206\u4e3a\u5b58\u50a8\u5c5e\u6027\u548c\u8ba1\u7b97\u5c5e\u6027:<\/p>\n<table class=\"reference\">\n<tbody>\n<tr>\n<th><b>\u5b58\u50a8\u5c5e\u6027<\/b><\/th>\n<th><b>\u8ba1\u7b97\u5c5e\u6027<\/b><\/th>\n<\/tr>\n<tr>\n<td>\u5b58\u50a8\u5e38\u91cf\u6216\u53d8\u91cf\u4f5c\u4e3a\u5b9e\u4f8b\u7684\u4e00\u90e8\u5206<\/td>\n<td>\u8ba1\u7b97\uff08\u800c\u4e0d\u662f\u5b58\u50a8\uff09\u4e00\u4e2a\u503c <\/td>\n<\/tr>\n<tr>\n<td>\u7528\u4e8e\u7c7b\u548c\u7ed3\u6784\u4f53<\/td>\n<td>\u7528\u4e8e\u7c7b\u3001\u7ed3\u6784\u4f53\u548c\u679a\u4e3e<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u5b58\u50a8\u5c5e\u6027\u548c\u8ba1\u7b97\u5c5e\u6027\u901a\u5e38\u7528\u4e8e\u7279\u5b9a\u7c7b\u578b\u7684\u5b9e\u4f8b\u3002\n<\/p>\n<p>\u5c5e\u6027\u4e5f\u53ef\u4ee5\u76f4\u63a5\u7528\u4e8e\u7c7b\u578b\u672c\u8eab\uff0c\u8fd9\u79cd\u5c5e\u6027\u79f0\u4e3a\u7c7b\u578b\u5c5e\u6027\u3002\n<\/p>\n<p>\n\u53e6\u5916\uff0c\u8fd8\u53ef\u4ee5\u5b9a\u4e49\u5c5e\u6027\u89c2\u5bdf\u5668\u6765\u76d1\u63a7\u5c5e\u6027\u503c\u7684\u53d8\u5316\uff0c\u4ee5\u6b64\u6765\u89e6\u53d1\u4e00\u4e2a\u81ea\u5b9a\u4e49\u7684\u64cd\u4f5c\u3002\u5c5e\u6027\u89c2\u5bdf\u5668\u53ef\u4ee5\u6dfb\u52a0\u5230\u81ea\u5df1\u5199\u7684\u5b58\u50a8\u5c5e\u6027\u4e0a\uff0c\u4e5f\u53ef\u4ee5\u6dfb\u52a0\u5230\u4ece\u7236\u7c7b\u7ee7\u627f\u7684\u5c5e\u6027\u4e0a\u3002\n<\/p>\n<hr>\n<h2>\u5b58\u50a8\u5c5e\u6027<\/h2>\n<p>\n\u7b80\u5355\u6765\u8bf4\uff0c\u4e00\u4e2a\u5b58\u50a8\u5c5e\u6027\u5c31\u662f\u5b58\u50a8\u5728\u7279\u5b9a\u7c7b\u6216\u7ed3\u6784\u4f53\u7684\u5b9e\u4f8b\u91cc\u7684\u4e00\u4e2a\u5e38\u91cf\u6216\u53d8\u91cf\u3002<\/p>\n<p>\u5b58\u50a8\u5c5e\u6027\u53ef\u4ee5\u662f\u53d8\u91cf\u5b58\u50a8\u5c5e\u6027\uff08\u7528\u5173\u952e\u5b57var\u5b9a\u4e49\uff09\uff0c\u4e5f\u53ef\u4ee5\u662f\u5e38\u91cf\u5b58\u50a8\u5c5e\u6027\uff08\u7528\u5173\u952e\u5b57let\u5b9a\u4e49\uff09\u3002<\/p>\n<ul>\n<li>\n<p>\u53ef\u4ee5\u5728\u5b9a\u4e49\u5b58\u50a8\u5c5e\u6027\u7684\u65f6\u5019\u6307\u5b9a\u9ed8\u8ba4\u503c<\/p>\n<\/li>\n<li>\n<p>\u4e5f\u53ef\u4ee5\u5728\u6784\u9020\u8fc7\u7a0b\u4e2d\u8bbe\u7f6e\u6216\u4fee\u6539\u5b58\u50a8\u5c5e\u6027\u7684\u503c\uff0c\u751a\u81f3\u4fee\u6539\u5e38\u91cf\u5b58\u50a8\u5c5e\u6027\u7684\u503c<\/p>\n<\/li>\n<\/ul>\n<pre>\nimport Cocoa\n\nstruct Number\n{\n   var digits: Int\n   let pi = 3.1415\n}\n\nvar n = Number(digits: 12345)\nn.digits = 67\n\nprint(\"\\(n.digits)\")\nprint(\"\\(n.pi)\")\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n67\n3.1415\n<\/pre>\n<p>\u8003\u8651\u4ee5\u4e0b\u4ee3\u7801\uff1a<\/p>\n<pre>let pi = 3.1415<\/pre>\n<p>\u4ee3\u7801\u4e2d pi \u5728\u5b9a\u4e49\u5b58\u50a8\u5c5e\u6027\u7684\u65f6\u5019\u6307\u5b9a\u9ed8\u8ba4\u503c\uff08pi = 3.1415\uff09\uff0c\u6240\u4ee5\u4e0d\u7ba1\u4f60\u4ec0\u4e48\u65f6\u5019\u5b9e\u4f8b\u5316\u7ed3\u6784\u4f53\uff0c\u5b83\u90fd\u4e0d\u4f1a\u6539\u53d8\u3002<\/p>\n<p>\u5982\u679c\u4f60\u5b9a\u4e49\u7684\u662f\u4e00\u4e2a\u5e38\u91cf\u5b58\u50a8\u5c5e\u6027\uff0c\u5982\u679c\u5c1d\u8bd5\u4fee\u6539\u5b83\u5c31\u4f1a\u62a5\u9519\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre>\nimport Cocoa\n\nstruct Number\n{\n    var digits: Int\n    let numbers = 3.1415\n}\n\nvar n = Number(digits: 12345)\nn.digits = 67\n\nprint(\"\\(n.digits)\")\nprint(\"\\(n.numbers)\")\nn.numbers = 8.7\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\uff0c\u6267\u884c\u4f1a\u62a5\u9519\uff0c\u9519\u8bef\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre>\nerror: cannot assign to property: 'numbers' is a 'let' constant\nn.numbers = 8.7\n<\/pre>\n<p>\u610f\u601d\u4e3a &#8216;numbers&#8217; \u662f\u4e00\u4e2a\u5e38\u91cf\uff0c\u4f60\u4e0d\u80fd\u4fee\u6539\u5b83\u3002<\/p>\n<hr>\n<h2>\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027<\/h2>\n<p>\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027\u662f\u6307\u5f53\u7b2c\u4e00\u6b21\u88ab\u8c03\u7528\u7684\u65f6\u5019\u624d\u4f1a\u8ba1\u7b97\u5176\u521d\u59cb\u503c\u7684\u5c5e\u6027\u3002<\/p>\n<p>\u5728\u5c5e\u6027\u58f0\u660e\u524d\u4f7f\u7528 <b>lazy<\/b> \u6765\u6807\u793a\u4e00\u4e2a\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027\u3002<\/p>\n<blockquote>\n<p>\u6ce8\u610f\uff1a<br \/>\u5fc5\u987b\u5c06\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027\u58f0\u660e\u6210\u53d8\u91cf\uff08\u4f7f\u7528<code>var<\/code>\u5173\u952e\u5b57\uff09\uff0c\u56e0\u4e3a\u5c5e\u6027\u7684\u503c\u5728\u5b9e\u4f8b\u6784\u9020\u5b8c\u6210\u4e4b\u524d\u53ef\u80fd\u65e0\u6cd5\u5f97\u5230\u3002\u800c\u5e38\u91cf\u5c5e\u6027\u5728\u6784\u9020\u8fc7\u7a0b\u5b8c\u6210\u4e4b\u524d\u5fc5\u987b\u8981\u6709\u521d\u59cb\u503c\uff0c\u56e0\u6b64\u65e0\u6cd5\u58f0\u660e\u6210\u5ef6\u8fdf\u5c5e\u6027\u3002  <\/p>\n<\/blockquote>\n<p>\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027\u4e00\u822c\u7528\u4e8e\uff1a<\/p>\n<ul>\n<li>\n<p>\u5ef6\u8fdf\u5bf9\u8c61\u7684\u521b\u5efa\u3002<\/p>\n<\/li>\n<li>\n<p>\u5f53\u5c5e\u6027\u7684\u503c\u4f9d\u8d56\u4e8e\u5176\u4ed6\u672a\u77e5\u7c7b<\/p>\n<\/li>\n<\/ul>\n<pre>\nimport Cocoa\n\nclass sample {\n    lazy var no = number() \/\/ `var` \u5173\u952e\u5b57\u662f\u5fc5\u987b\u7684\n}\n\nclass number {\n    var name = \"Runoob Swift \u6559\u7a0b\"\n}\n\nvar firstsample = sample()\nprint(firstsample.no.name)\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nRunoob Swift \u6559\u7a0b\n<\/pre>\n<hr>\n<h2>\u5b9e\u4f8b\u5316\u53d8\u91cf<\/h2>\n<p>\u5982\u679c\u60a8\u6709\u8fc7 Objective-C \u7ecf\u9a8c\uff0c\u5e94\u8be5\u77e5\u9053Objective-C \u4e3a\u7c7b\u5b9e\u4f8b\u5b58\u50a8\u503c\u548c\u5f15\u7528\u63d0\u4f9b\u4e24\u79cd\u65b9\u6cd5\u3002\u5bf9\u4e8e\u5c5e\u6027\u6765\u8bf4\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528\u5b9e\u4f8b\u53d8\u91cf\u4f5c\u4e3a\u5c5e\u6027\u503c\u7684\u540e\u7aef\u5b58\u50a8\u3002<\/p>\n<p>Swift \u7f16\u7a0b\u8bed\u8a00\u4e2d\u628a\u8fd9\u4e9b\u7406\u8bba\u7edf\u4e00\u7528\u5c5e\u6027\u6765\u5b9e\u73b0\u3002Swift \u4e2d\u7684\u5c5e\u6027\u6ca1\u6709\u5bf9\u5e94\u7684\u5b9e\u4f8b\u53d8\u91cf\uff0c\u5c5e\u6027\u7684\u540e\u7aef\u5b58\u50a8\u4e5f\u65e0\u6cd5\u76f4\u63a5\u8bbf\u95ee\u3002\u8fd9\u5c31\u907f\u514d\u4e86\u4e0d\u540c\u573a\u666f\u4e0b\u8bbf\u95ee\u65b9\u5f0f\u7684\u56f0\u6270\uff0c\u540c\u65f6\u4e5f\u5c06\u5c5e\u6027\u7684\u5b9a\u4e49\u7b80\u5316\u6210\u4e00\u4e2a\u8bed\u53e5\u3002<\/p>\n<p>\n\u4e00\u4e2a\u7c7b\u578b\u4e2d\u5c5e\u6027\u7684\u5168\u90e8\u4fe1\u606f\u2014\u2014\u5305\u62ec\u547d\u540d\u3001\u7c7b\u578b\u548c\u5185\u5b58\u7ba1\u7406\u7279\u5f81\u2014\u2014\u90fd\u5728\u552f\u4e00\u4e00\u4e2a\u5730\u65b9\uff08\u7c7b\u578b\u5b9a\u4e49\u4e2d\uff09\u5b9a\u4e49\u3002<\/p>\n<hr>\n<h2>\u8ba1\u7b97\u5c5e\u6027<\/h2>\n<p>\u9664\u5b58\u50a8\u5c5e\u6027\u5916\uff0c\u7c7b\u3001\u7ed3\u6784\u4f53\u548c\u679a\u4e3e\u53ef\u4ee5\u5b9a\u4e49<em>\u8ba1\u7b97\u5c5e\u6027<\/em>\uff0c\u8ba1\u7b97\u5c5e\u6027\u4e0d\u76f4\u63a5\u5b58\u50a8\u503c\uff0c\u800c\u662f\u63d0\u4f9b\u4e00\u4e2a getter \u6765\u83b7\u53d6\u503c\uff0c\u4e00\u4e2a\u53ef\u9009\u7684 setter \u6765\u95f4\u63a5\u8bbe\u7f6e\u5176\u4ed6\u5c5e\u6027\u6216\u53d8\u91cf\u7684\u503c\u3002<\/p>\n<pre>\nimport Cocoa\n\nclass sample {\n    var no1 = 0.0, no2 = 0.0\n    var length = 300.0, breadth = 150.0\n    \n    var middle: (Double, Double) {\n        get{\n            return (length \/ 2, breadth \/ 2)\n        }\n        set(axis){\n            no1 = axis.0 - (length \/ 2)\n            no2 = axis.1 - (breadth \/ 2)\n        }\n    }\n}\n\nvar result = sample()\nprint(result.middle)\nresult.middle = (0.0, 10.0)\n\nprint(result.no1)\nprint(result.no2)\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n(150.0, 75.0)\n-150.0\n-65.0\n<\/pre>\n<p>\n\u5982\u679c\u8ba1\u7b97\u5c5e\u6027\u7684 setter \u6ca1\u6709\u5b9a\u4e49\u8868\u793a\u65b0\u503c\u7684\u53c2\u6570\u540d\uff0c\u5219\u53ef\u4ee5\u4f7f\u7528\u9ed8\u8ba4\u540d\u79f0 newValue\u3002\n<\/p>\n<hr>\n<h2>\u53ea\u8bfb\u8ba1\u7b97\u5c5e\u6027<\/h2>\n<p>\u53ea\u6709 getter \u6ca1\u6709 setter \u7684\u8ba1\u7b97\u5c5e\u6027\u5c31\u662f\u53ea\u8bfb\u8ba1\u7b97\u5c5e\u6027\u3002<\/p>\n<p>\u53ea\u8bfb\u8ba1\u7b97\u5c5e\u6027\u603b\u662f\u8fd4\u56de\u4e00\u4e2a\u503c\uff0c\u53ef\u4ee5\u901a\u8fc7\u70b9(.)\u8fd0\u7b97\u7b26\u8bbf\u95ee\uff0c\u4f46\u4e0d\u80fd\u8bbe\u7f6e\u65b0\u7684\u503c\u3002<\/p>\n<pre>\nimport Cocoa\n\nclass film {\n    var head = \"\"\n    var duration = 0.0\n    var metaInfo: [String:String] {\n        return [\n            \"head\": self.head,\n            \"duration\":\"\\(self.duration)\"\n        ]\n    }\n}\n\nvar movie = film()\nmovie.head = \"Swift \u5c5e\u6027\"\nmovie.duration = 3.09\n\nprint(movie.metaInfo[\"head\"]!)\nprint(movie.metaInfo[\"duration\"]!)\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nSwift \u5c5e\u6027\n3.09\n<\/pre>\n<blockquote>\n<p>\u6ce8\u610f\uff1a<\/p>\n<p>\u5fc5\u987b\u4f7f\u7528<code>var<\/code>\u5173\u952e\u5b57\u5b9a\u4e49\u8ba1\u7b97\u5c5e\u6027\uff0c\u5305\u62ec\u53ea\u8bfb\u8ba1\u7b97\u5c5e\u6027\uff0c\u56e0\u4e3a\u5b83\u4eec\u7684\u503c\u4e0d\u662f\u56fa\u5b9a\u7684\u3002<code>let<\/code>\u5173\u952e\u5b57\u53ea\u7528\u6765\u58f0\u660e\u5e38\u91cf\u5c5e\u6027\uff0c\u8868\u793a\u521d\u59cb\u5316\u540e\u518d\u4e5f\u65e0\u6cd5\u4fee\u6539\u7684\u503c\u3002<\/p>\n<\/blockquote>\n<hr>\n<h2>\u5c5e\u6027\u89c2\u5bdf\u5668<\/h2>\n<p>\u5c5e\u6027\u89c2\u5bdf\u5668\u76d1\u63a7\u548c\u54cd\u5e94\u5c5e\u6027\u503c\u7684\u53d8\u5316\uff0c\u6bcf\u6b21\u5c5e\u6027\u88ab\u8bbe\u7f6e\u503c\u7684\u65f6\u5019\u90fd\u4f1a\u8c03\u7528\u5c5e\u6027\u89c2\u5bdf\u5668\uff0c\u751a\u81f3\u65b0\u7684\u503c\u548c\u73b0\u5728\u7684\u503c\u76f8\u540c\u7684\u65f6\u5019\u4e5f\u4e0d\u4f8b\u5916\u3002<\/p>\n<p>\u53ef\u4ee5\u4e3a\u9664\u4e86\u5ef6\u8fdf\u5b58\u50a8\u5c5e\u6027\u4e4b\u5916\u7684\u5176\u4ed6\u5b58\u50a8\u5c5e\u6027\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\uff0c\u4e5f\u53ef\u4ee5\u901a\u8fc7\u91cd\u8f7d\u5c5e\u6027\u7684\u65b9\u5f0f\u4e3a\u7ee7\u627f\u7684\u5c5e\u6027\uff08\u5305\u62ec\u5b58\u50a8\u5c5e\u6027\u548c\u8ba1\u7b97\u5c5e\u6027\uff09\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\u3002<\/p>\n<blockquote>\n<p>\u6ce8\u610f\uff1a<br \/>\u4e0d\u9700\u8981\u4e3a\u65e0\u6cd5\u91cd\u8f7d\u7684\u8ba1\u7b97\u5c5e\u6027\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\uff0c\u56e0\u4e3a\u53ef\u4ee5\u901a\u8fc7 setter \u76f4\u63a5\u76d1\u63a7\u548c\u54cd\u5e94\u503c\u7684\u53d8\u5316\u3002  <\/p>\n<\/blockquote>\n<p>\u53ef\u4ee5\u4e3a\u5c5e\u6027\u6dfb\u52a0\u5982\u4e0b\u7684\u4e00\u4e2a\u6216\u5168\u90e8\u89c2\u5bdf\u5668\uff1a<\/p>\n<ul>\n<li><code>willSet<\/code>\u5728\u8bbe\u7f6e\u65b0\u7684\u503c\u4e4b\u524d\u8c03\u7528<\/li>\n<li><code>didSet<\/code>\u5728\u65b0\u7684\u503c\u88ab\u8bbe\u7f6e\u4e4b\u540e\u7acb\u5373\u8c03\u7528<\/li>\n<li>willSet\u548cdidSet\u89c2\u5bdf\u5668\u5728\u5c5e\u6027\u521d\u59cb\u5316\u8fc7\u7a0b\u4e2d\u4e0d\u4f1a\u88ab\u8c03\u7528<\/li>\n<\/ul>\n<pre>\nimport Cocoa\n\nclass Samplepgm {\n    var counter: Int = 0{\n        willSet(newTotal){\n            print(\"\u8ba1\u6570\u5668: \\(newTotal)\")\n        }\n        didSet{\n            if counter &gt; oldValue {\n                print(\"\u65b0\u589e\u6570 \\(counter - oldValue)\")\n            }\n        }\n    }\n}\nlet NewCounter = Samplepgm()\nNewCounter.counter = 100\nNewCounter.counter = 800\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n\u8ba1\u6570\u5668: 100\n\u65b0\u589e\u6570 100\n\u8ba1\u6570\u5668: 800\n\u65b0\u589e\u6570 700\n<\/pre>\n<hr>\n<h2>\u5168\u5c40\u53d8\u91cf\u548c\u5c40\u90e8\u53d8\u91cf<\/h2>\n<p>\u8ba1\u7b97\u5c5e\u6027\u548c\u5c5e\u6027\u89c2\u5bdf\u5668\u6240\u63cf\u8ff0\u7684\u6a21\u5f0f\u4e5f\u53ef\u4ee5\u7528\u4e8e\u5168\u5c40\u53d8\u91cf\u548c\u5c40\u90e8\u53d8\u91cf\u3002<\/p>\n<table class=\"reference\">\n<tbody>\n<tr>\n<th><b>\u5c40\u90e8\u53d8\u91cf<\/b><\/th>\n<th><b>\u5168\u5c40\u53d8\u91cf<\/b><\/th>\n<\/tr>\n<tr>\n<td>\u5728\u51fd\u6570\u3001\u65b9\u6cd5\u6216\u95ed\u5305\u5185\u90e8\u5b9a\u4e49\u7684\u53d8\u91cf\u3002<\/td>\n<td>\u51fd\u6570\u3001\u65b9\u6cd5\u3001\u95ed\u5305\u6216\u4efb\u4f55\u7c7b\u578b\u4e4b\u5916\u5b9a\u4e49\u7684\u53d8\u91cf\u3002<\/td>\n<\/tr>\n<tr>\n<td>\u7528\u4e8e\u5b58\u50a8\u548c\u68c0\u7d22\u503c\u3002<\/td>\n<td>\u7528\u4e8e\u5b58\u50a8\u548c\u68c0\u7d22\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>\u5b58\u50a8\u5c5e\u6027\u7528\u4e8e\u83b7\u53d6\u548c\u8bbe\u7f6e\u503c\u3002<\/td>\n<td>\u5b58\u50a8\u5c5e\u6027\u7528\u4e8e\u83b7\u53d6\u548c\u8bbe\u7f6e\u503c\u3002<\/td>\n<\/tr>\n<tr>\n<td>\u4e5f\u7528\u4e8e\u8ba1\u7b97\u5c5e\u6027\u3002<\/td>\n<td>\u4e5f\u7528\u4e8e\u8ba1\u7b97\u5c5e\u6027\u3002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr>\n<h2>\u7c7b\u578b\u5c5e\u6027<\/h2>\n<p>\u7c7b\u578b\u5c5e\u6027\u662f\u4f5c\u4e3a\u7c7b\u578b\u5b9a\u4e49\u7684\u4e00\u90e8\u5206\u5199\u5728\u7c7b\u578b\u6700\u5916\u5c42\u7684\u82b1\u62ec\u53f7\uff08{}\uff09\u5185\u3002<\/p>\n<p>\u4f7f\u7528\u5173\u952e\u5b57 static \u6765\u5b9a\u4e49\u503c\u7c7b\u578b\u7684\u7c7b\u578b\u5c5e\u6027\uff0c\u5173\u952e\u5b57 class \u6765\u4e3a\u7c7b\u5b9a\u4e49\u7c7b\u578b\u5c5e\u6027\u3002<\/p>\n<pre>\nstruct Structname {\n   static var storedTypeProperty = \" \"\n   static var computedTypeProperty: Int {\n      \/\/ \u8fd9\u91cc\u8fd4\u56de\u4e00\u4e2a Int \u503c\n   }\n}\n\nenum Enumname {\n   static var storedTypeProperty = \" \"\n   static var computedTypeProperty: Int {\n      \/\/ \u8fd9\u91cc\u8fd4\u56de\u4e00\u4e2a Int \u503c\n   }\n}\n\nclass Classname {\n   class var computedTypeProperty: Int {\n      \/\/ \u8fd9\u91cc\u8fd4\u56de\u4e00\u4e2a Int \u503c\n   }\n}\n<\/pre>\n<blockquote>\n<p>\u6ce8\u610f\uff1a<br \/>\u4f8b\u5b50\u4e2d\u7684\u8ba1\u7b97\u578b\u7c7b\u578b\u5c5e\u6027\u662f\u53ea\u8bfb\u7684\uff0c\u4f46\u4e5f\u53ef\u4ee5\u5b9a\u4e49\u53ef\u8bfb\u53ef\u5199\u7684\u8ba1\u7b97\u578b\u7c7b\u578b\u5c5e\u6027\uff0c\u8ddf\u5b9e\u4f8b\u8ba1\u7b97\u5c5e\u6027\u7684\u8bed\u6cd5\u7c7b\u4f3c\u3002  <\/p>\n<\/blockquote>\n<hr>\n<h2>\u83b7\u53d6\u548c\u8bbe\u7f6e\u7c7b\u578b\u5c5e\u6027\u7684\u503c<\/h2>\n<p>\n\u7c7b\u4f3c\u4e8e\u5b9e\u4f8b\u7684\u5c5e\u6027\uff0c\u7c7b\u578b\u5c5e\u6027\u7684\u8bbf\u95ee\u4e5f\u662f\u901a\u8fc7\u70b9\u8fd0\u7b97\u7b26(.)\u6765\u8fdb\u884c\u3002\u4f46\u662f\uff0c\u7c7b\u578b\u5c5e\u6027\u662f\u901a\u8fc7\u7c7b\u578b\u672c\u8eab\u6765\u83b7\u53d6\u548c\u8bbe\u7f6e\uff0c\u800c\u4e0d\u662f\u901a\u8fc7\u5b9e\u4f8b\u3002\u5b9e\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>\nimport Cocoa\n\nstruct StudMarks {\n   static let markCount = 97\n   static var totalCount = 0\n   var InternalMarks: Int = 0 {\n      didSet {\n         if InternalMarks &gt; StudMarks.markCount {\n            InternalMarks = StudMarks.markCount\n         }\n         if InternalMarks &gt; StudMarks.totalCount {\n            StudMarks.totalCount = InternalMarks\n         }\n      }\n   }\n}\n\nvar stud1Mark1 = StudMarks()\nvar stud1Mark2 = StudMarks()\n\nstud1Mark1.InternalMarks = 98\nprint(stud1Mark1.InternalMarks) \n\nstud1Mark2.InternalMarks = 87\nprint(stud1Mark2.InternalMarks)\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n97\n87\n<\/pre>\n<\/p><\/div>\n<\/p><\/div>\n<span>","protected":false},"excerpt":{"rendered":"<p class=\"excerpt\"><span itemprop=\"description\">Swift \u5c5e\u6027 Swift \u5c5e\u6027\u5c06\u503c\u8ddf\u7279\u5b9a\u7684\u7c7b\u3001\u7ed3\u6784\u6216\u679a\u4e3e\u5173\u8054\u3002 \u5c5e\u6027\u53ef\u5206\u4e3a\u5b58\u50a8\u5c5e\u6027\u548c\u8ba1&hellip;<\/span><\/p>\n<p class=\"more-link-p btn-align-right\"><a class=\"green zoom-btn\" href=\"https:\/\/www.puzi7.net\/?p=538\">Read More<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26,28],"tags":[74,119],"class_list":["post-538","post","type-post","status-publish","format-standard","hentry","category-mobile","category-swift","tag-ios","tag-swift","zoom-theme-has-thumb"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.3 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Swift \u5c5e\u6027 - \u8c31\u5b50\u68cb - Puzi7<\/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.puzi7.net\/?p=538\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Swift \u5c5e\u6027 - \u8c31\u5b50\u68cb - Puzi7\" \/>\n<meta property=\"og:description\" content=\"Swift \u5c5e\u6027 Swift \u5c5e\u6027\u5c06\u503c\u8ddf\u7279\u5b9a\u7684\u7c7b\u3001\u7ed3\u6784\u6216\u679a\u4e3e\u5173\u8054\u3002 \u5c5e\u6027\u53ef\u5206\u4e3a\u5b58\u50a8\u5c5e\u6027\u548c\u8ba1&hellip;Read More\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.puzi7.net\/?p=538\" \/>\n<meta property=\"og:site_name\" content=\"\u8c31\u5b50\u68cb - Puzi7\" \/>\n<meta property=\"article:published_time\" content=\"2018-02-23T15:39:05+00:00\" \/>\n<meta name=\"author\" content=\"\u77f3\u8863\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"\u77f3\u8863\" \/>\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\" 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