{"id":541,"date":"2018-02-23T23:39:06","date_gmt":"2018-02-23T15:39:06","guid":{"rendered":"http:\/\/60.205.208.74\/2018\/02\/23\/swift-%e7%bb%a7%e6%89%bf\/"},"modified":"2018-02-23T23:39:06","modified_gmt":"2018-02-23T15:39:06","slug":"swift-%e7%bb%a7%e6%89%bf","status":"publish","type":"post","link":"https:\/\/www.puzi7.net\/?p=541","title":{"rendered":"Swift \u7ee7\u627f"},"content":{"rendered":"<span itemprop=\"description\"><div class=\"article-body\">\n<div class=\"article-intro\" id=\"content\">\n<h1>Swift \u7ee7\u627f<\/h1>\n<p>\u7ee7\u627f\u6211\u4eec\u53ef\u4ee5\u7406\u89e3\u4e3a\u4e00\u4e2a\u7c7b\u83b7\u53d6\u4e86\u53e6\u5916\u4e00\u4e2a\u7c7b\u7684\u65b9\u6cd5\u548c\u5c5e\u6027\u3002<\/p>\n<p>\u5f53\u4e00\u4e2a\u7c7b\u7ee7\u627f\u5176\u5b83\u7c7b\u65f6\uff0c\u7ee7\u627f\u7c7b\u53eb\u5b50\u7c7b\uff0c\u88ab\u7ee7\u627f\u7c7b\u53eb\u8d85\u7c7b\uff08\u6216\u7236\u7c7b)<\/p>\n<p>\u5728 Swift \u4e2d\uff0c\u7c7b\u53ef\u4ee5\u8c03\u7528\u548c\u8bbf\u95ee\u8d85\u7c7b\u7684\u65b9\u6cd5\uff0c\u5c5e\u6027\u548c\u4e0b\u6807\u811a\u672c\uff0c\u5e76\u4e14\u53ef\u4ee5\u91cd\u5199\u5b83\u4eec\u3002<\/p>\n<p>\u6211\u4eec\u4e5f\u53ef\u4ee5\u4e3a\u7c7b\u4e2d\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\u3002<\/p>\n<hr>\n<h2>\u57fa\u7c7b<\/h2>\n<p>\u6ca1\u6709\u7ee7\u627f\u5176\u5b83\u7c7b\u7684\u7c7b\uff0c\u79f0\u4e4b\u4e3a\u57fa\u7c7b\uff08Base Class\uff09\u3002<\/p>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u4e2d\u6211\u4eec\u5b9a\u4e49\u4e86\u57fa\u7c7b StudDetails \uff0c\u63cf\u8ff0\u4e86\u5b66\u751f\uff08stname\uff09\u53ca\u5176\u5404\u79d1\u6210\u7ee9\u7684\u5206\u6570(mark1\u3001mark2\u3001mark3)\uff1a<\/p>\n<pre>\nclass StudDetails {\n    var stname: String!\n    var mark1: Int!\n    var mark2: Int!\n    var mark3: Int!\n    init(stname: String, mark1: Int, mark2: Int, mark3: Int) {\n        self.stname = stname\n        self.mark1 = mark1\n        self.mark2 = mark2\n        self.mark3 = mark3\n    }\n}\nlet stname = \"swift\"\nlet mark1 = 98\nlet mark2 = 89\nlet mark3 = 76\n\nlet sds = StudDetails(stname:stname, mark1:mark1, mark2:mark2, mark3:mark3);\n\nprint(sds.stname)\nprint(sds.mark1)\nprint(sds.mark2)\nprint(sds.mark3)\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nswift\n98\n89\n76\n<\/pre>\n<hr>\n<h2>\u5b50\u7c7b<br \/>\n<\/h2>\n<p>\u5b50\u7c7b\u6307\u7684\u662f\u5728\u4e00\u4e2a\u5df2\u6709\u7c7b\u7684\u57fa\u7840\u4e0a\u521b\u5efa\u4e00\u4e2a\u65b0\u7684\u7c7b\u3002<\/p>\n<p>\u4e3a\u4e86\u6307\u660e\u67d0\u4e2a\u7c7b\u7684\u8d85\u7c7b\uff0c\u5c06\u8d85\u7c7b\u540d\u5199\u5728\u5b50\u7c7b\u540d\u7684\u540e\u9762\uff0c\u7528\u5192\u53f7(:)\u5206\u9694,\u8bed\u6cd5\u683c\u5f0f\u5982\u4e0b<\/p>\n<pre>\nclass SomeClass: SomeSuperclass {\n    \/\/ \u7c7b\u7684\u5b9a\u4e49\n}\n<\/pre>\n<h3>\u5b9e\u4f8b<\/h3>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u4e2d\u6211\u4eec\u5b9a\u4e49\u4e86\u8d85\u7c7b StudDetails\uff0c\u7136\u540e\u4f7f\u7528\u5b50\u7c7b Tom \u7ee7\u627f\u5b83\uff1a<\/p>\n<pre>\nclass StudDetails\n{\n    var mark1: Int;\n    var mark2: Int;\n    \n    init(stm1:Int, results stm2:Int)\n    {\n        mark1 = stm1;\n        mark2 = stm2;\n    }\n    \n    func show()\n    {\n        print(\"Mark1:\\(self.mark1), Mark2:\\(self.mark2)\")\n    }\n}\n\nclass Tom : StudDetails\n{\n    init()\n    {\n        super.init(stm1: 93, results: 89)\n    }\n}\n\nlet tom = Tom()\ntom.show()\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nMark1:93, Mark2:89\n<\/pre>\n<hr>\n<h2>\u91cd\u5199\uff08Overriding\uff09<\/h2>\n<p>\u5b50\u7c7b\u53ef\u4ee5\u901a\u8fc7\u7ee7\u627f\u6765\u7684\u5b9e\u4f8b\u65b9\u6cd5\uff0c\u7c7b\u65b9\u6cd5\uff0c\u5b9e\u4f8b\u5c5e\u6027\uff0c\u6216\u4e0b\u6807\u811a\u672c\u6765\u5b9e\u73b0\u81ea\u5df1\u7684\u5b9a\u5236\u529f\u80fd\uff0c\u6211\u4eec\u628a\u8fd9\u79cd\u884c\u4e3a\u53eb\u91cd\u5199\uff08overriding\uff09\u3002<\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 override \u5173\u952e\u5b57\u6765\u5b9e\u73b0\u91cd\u5199\u3002<\/p>\n<h3>\u8bbf\u95ee\u8d85\u7c7b\u7684\u65b9\u6cd5\u3001\u5c5e\u6027\u53ca\u4e0b\u6807\u811a\u672c<\/h3>\n<p>\u4f60\u53ef\u4ee5\u901a\u8fc7\u4f7f\u7528super\u524d\u7f00\u6765\u8bbf\u95ee\u8d85\u7c7b\u7684\u65b9\u6cd5\uff0c\u5c5e\u6027\u6216\u4e0b\u6807\u811a\u672c\u3002<\/p>\n<table class=\"reference\">\n<tbody>\n<tr>\n<th>\u91cd\u5199<\/th>\n<th>\u8bbf\u95ee\u65b9\u6cd5\uff0c\u5c5e\u6027\uff0c\u4e0b\u6807\u811a\u672c<\/th>\n<\/tr>\n<tr>\n<td>\u65b9\u6cd5<\/td>\n<td>super.somemethod()<\/td>\n<\/tr>\n<tr>\n<td>\u5c5e\u6027<\/td>\n<td>super.someProperty()<\/td>\n<\/tr>\n<tr>\n<td>\u4e0b\u6807\u811a\u672c<\/td>\n<td>super[someIndex]<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr>\n<h2>\u91cd\u5199\u65b9\u6cd5\u548c\u5c5e\u6027<\/h2>\n<h3>\u91cd\u5199\u65b9\u6cd5<\/h3>\n<p>\u5728\u6211\u4eec\u7684\u5b50\u7c7b\u4e2d\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 override \u5173\u952e\u5b57\u6765\u91cd\u5199\u8d85\u7c7b\u7684\u65b9\u6cd5\u3002<\/p>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u4e2d\u6211\u4eec\u91cd\u5199\u4e86 show() \u65b9\u6cd5\uff1a<\/p>\n<pre>\nclass SuperClass {\n    func show() {\n        print(\"\u8fd9\u662f\u8d85\u7c7b SuperClass\")\n    }\n}\n\nclass SubClass: SuperClass  {\n    override func show() {\n        print(\"\u8fd9\u662f\u5b50\u7c7b SubClass\")\n    }\n}\n\nlet superClass = SuperClass()\nsuperClass.show()\n\nlet subClass = SubClass()\nsubClass.show()\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n\u8fd9\u662f\u8d85\u7c7b SuperClass\n\u8fd9\u662f\u5b50\u7c7b SubClass\n<\/pre>\n<h3>\u91cd\u5199\u5c5e\u6027<\/h3>\n<p>\u4f60\u53ef\u4ee5\u63d0\u4f9b\u5b9a\u5236\u7684 getter\uff08\u6216 setter\uff09\u6765\u91cd\u5199\u4efb\u610f\u7ee7\u627f\u6765\u7684\u5c5e\u6027\uff0c\u65e0\u8bba\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u662f\u5b58\u50a8\u578b\u7684\u8fd8\u662f\u8ba1\u7b97\u578b\u7684\u5c5e\u6027\u3002<\/p>\n<p>\u5b50\u7c7b\u5e76\u4e0d\u77e5\u9053\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u662f\u5b58\u50a8\u578b\u7684\u8fd8\u662f\u8ba1\u7b97\u578b\u7684\uff0c\u5b83\u53ea\u77e5\u9053\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u4f1a\u6709\u4e00\u4e2a\u540d\u5b57\u548c\u7c7b\u578b\u3002\u6240\u4ee5\u4f60\u5728\u91cd\u5199\u4e00\u4e2a\u5c5e\u6027\u65f6\uff0c\u5fc5\u9700\u5c06\u5b83\u7684\u540d\u5b57\u548c\u7c7b\u578b\u90fd\u5199\u51fa\u6765\u3002<\/p>\n<p>\u6ce8\u610f\u70b9\uff1a<\/p>\n<ul>\n<li>\n<p>\u5982\u679c\u4f60\u5728\u91cd\u5199\u5c5e\u6027\u4e2d\u63d0\u4f9b\u4e86 setter\uff0c\u90a3\u4e48\u4f60\u4e5f\u4e00\u5b9a\u8981\u63d0\u4f9b getter\u3002<\/p>\n<\/li>\n<li>\n<p>\u5982\u679c\u4f60\u4e0d\u60f3\u5728\u91cd\u5199\u7248\u672c\u4e2d\u7684 getter \u91cc\u4fee\u6539\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u503c\uff0c\u4f60\u53ef\u4ee5\u76f4\u63a5\u901a\u8fc7super.someProperty\u6765\u8fd4\u56de\u7ee7\u627f\u6765\u7684\u503c\uff0c\u5176\u4e2dsomeProperty\u662f\u4f60\u8981\u91cd\u5199\u7684\u5c5e\u6027\u7684\u540d\u5b57\u3002<\/p>\n<\/li>\n<\/ul>\n<p>\u4ee5\u4e0b\u5b9e\u4f8b\u6211\u4eec\u5b9a\u4e49\u4e86\u8d85\u7c7b Circle \u53ca\u5b50\u7c7b Rectangle, \u5728 Rectangle \u7c7b\u4e2d\u6211\u4eec\u91cd\u5199\u5c5e\u6027 area\uff1a<\/p>\n<pre>\nclass Circle {\n    var radius = 12.5\n    var area: String {\n        return \"\u77e9\u5f62\u534a\u5f84 \\(radius) \"\n    }\n}\n\n\/\/ \u7ee7\u627f\u8d85\u7c7b Circle\nclass Rectangle: Circle {\n    var print = 7\n    override var area: String {\n        return super.area + \" \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a \\(print)\"\n    }\n}\n\nlet rect = Rectangle()\nrect.radius = 25.0\nrect.print = 3\nprint(\"Radius \\(rect.area)\")\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nRadius \u77e9\u5f62\u534a\u5f84 25.0  \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a 3\n<\/pre>\n<hr>\n<h2>\u91cd\u5199\u5c5e\u6027\u89c2\u5bdf\u5668<\/h2>\n<p>\u4f60\u53ef\u4ee5\u5728\u5c5e\u6027\u91cd\u5199\u4e2d\u4e3a\u4e00\u4e2a\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\u3002\u8fd9\u6837\u4e00\u6765\uff0c\u5f53\u7ee7\u627f\u6765\u7684\u5c5e\u6027\u503c\u53d1\u751f\u6539\u53d8\u65f6\uff0c\u4f60\u5c31\u4f1a\u76d1\u6d4b\u5230\u3002<\/p>\n<p><b>\u6ce8\u610f\uff1a<\/b>\u4f60\u4e0d\u53ef\u4ee5\u4e3a\u7ee7\u627f\u6765\u7684\u5e38\u91cf\u5b58\u50a8\u578b\u5c5e\u6027\u6216\u7ee7\u627f\u6765\u7684\u53ea\u8bfb\u8ba1\u7b97\u578b\u5c5e\u6027\u6dfb\u52a0\u5c5e\u6027\u89c2\u5bdf\u5668\u3002<\/p>\n<pre>\nclass Circle {\n    var radius = 12.5\n    var area: String {\n        return \"\u77e9\u5f62\u534a\u5f84\u4e3a \\(radius) \"\n    }\n}\n\nclass Rectangle: Circle {\n    var print = 7\n    override var area: String {\n        return super.area + \" \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a \\(print)\"\n    }\n}\n\n\nlet rect = Rectangle()\nrect.radius = 25.0\nrect.print = 3\nprint(\"\u534a\u5f84: \\(rect.area)\")\n\nclass Square: Rectangle {\n    override var radius: Double {\n        didSet {\n            print = Int(radius\/5.0)+1\n        }\n    }\n}\n\n\nlet sq = Square()\nsq.radius = 100.0\nprint(\"\u534a\u5f84: \\(sq.area)\")\n<\/pre>\n<pre>\n\u534a\u5f84: \u77e9\u5f62\u534a\u5f84\u4e3a 25.0  \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a 3\n\u534a\u5f84: \u77e9\u5f62\u534a\u5f84\u4e3a 100.0  \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a 21\n<\/pre>\n<hr>\n<h2>\u9632\u6b62\u91cd\u5199<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 final \u5173\u952e\u5b57\u9632\u6b62\u5b83\u4eec\u88ab\u91cd\u5199\u3002<\/p>\n<p>\u5982\u679c\u4f60\u91cd\u5199\u4e86final\u65b9\u6cd5\uff0c\u5c5e\u6027\u6216\u4e0b\u6807\u811a\u672c\uff0c\u5728\u7f16\u8bd1\u65f6\u4f1a\u62a5\u9519\u3002<\/p>\n<p>\u4f60\u53ef\u4ee5\u901a\u8fc7\u5728\u5173\u952e\u5b57class\u524d\u6dfb\u52a0final\u7279\u6027\uff08final class\uff09\u6765\u5c06\u6574\u4e2a\u7c7b\u6807\u8bb0\u4e3a final \u7684\uff0c\u8fd9\u6837\u7684\u7c7b\u662f\u4e0d\u53ef\u88ab\u7ee7\u627f\u7684\uff0c\u5426\u5219\u4f1a\u62a5\u7f16\u8bd1\u9519\u8bef\u3002<\/p>\n<pre>\nfinal class Circle {\n    final var radius = 12.5\n    var area: String {\n        return \"\u77e9\u5f62\u534a\u5f84\u4e3a \\(radius) \"\n    }\n}\nclass Rectangle: Circle {\n    var print = 7\n    override var area: String {\n        return super.area + \" \uff0c\u4f46\u73b0\u5728\u88ab\u91cd\u5199\u4e3a \\(print)\"\n    }\n}\n\nlet rect = Rectangle()\nrect.radius = 25.0\nrect.print = 3\nprint(\"\u534a\u5f84: \\(rect.area)\")\n\nclass Square: Rectangle {\n    override var radius: Double {\n        didSet {\n            print = Int(radius\/5.0)+1\n        }\n    }\n}\n\nlet sq = Square()\nsq.radius = 100.0\nprint(\"\u534a\u5f84: \\(sq.area)\")\n<\/pre>\n<p>\u7531\u4e8e\u4ee5\u4e0a\u5b9e\u4f8b\u4f7f\u7528\u4e86 final \u5173\u952e\u5b57\u4e0d\u5141\u8bb8\u91cd\u5199\uff0c\u6240\u4ee5\u6267\u884c\u4f1a\u62a5\u9519\uff1a<\/p>\n<pre>\nerror: var overrides a 'final' var\n    override var area: String {\n                 ^\nnote: overridden declaration is here\n    var area: String {\n        ^\nerror: var overrides a 'final' var\n    override var radius: Double {\n                 ^\nnote: overridden declaration is here\n    final var radius = 12.5\n              ^\nerror: inheritance from a final class 'Circle'\nclass Rectangle: Circle {\n      ^\n<\/pre>\n<\/p><\/div>\n<\/p><\/div>\n<span>","protected":false},"excerpt":{"rendered":"<p class=\"excerpt\"><span itemprop=\"description\">Swift \u7ee7\u627f \u7ee7\u627f\u6211\u4eec\u53ef\u4ee5\u7406\u89e3\u4e3a\u4e00\u4e2a\u7c7b\u83b7\u53d6\u4e86\u53e6\u5916\u4e00\u4e2a\u7c7b\u7684\u65b9\u6cd5\u548c\u5c5e\u6027\u3002 \u5f53\u4e00\u4e2a\u7c7b\u7ee7\u627f\u5176\u5b83&hellip;<\/span><\/p>\n<p class=\"more-link-p btn-align-right\"><a class=\"green zoom-btn\" href=\"https:\/\/www.puzi7.net\/?p=541\">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-541","post","type-post","status-publish","format-standard","hentry","category-mobile","category-swift","tag-ios","tag-swift","zoom-theme-has-thumb"],"_links":{"self":[{"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/posts\/541","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=541"}],"version-history":[{"count":0,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/posts\/541\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=541"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=541"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=541"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}