{"id":532,"date":"2018-02-23T23:39:02","date_gmt":"2018-02-23T15:39:02","guid":{"rendered":"http:\/\/60.205.208.74\/2018\/02\/23\/swift-%e5%ad%97%e5%85%b8\/"},"modified":"2018-02-23T23:39:02","modified_gmt":"2018-02-23T15:39:02","slug":"swift-%e5%ad%97%e5%85%b8","status":"publish","type":"post","link":"https:\/\/www.puzi7.net\/?p=532","title":{"rendered":"Swift \u5b57\u5178"},"content":{"rendered":"<span itemprop=\"description\"><div class=\"article-body\">\n<div class=\"article-intro\" id=\"content\">\n<h1>Swift \u5b57\u5178<\/h1>\n<p>Swift \u5b57\u5178\u7528\u6765\u5b58\u50a8\u65e0\u5e8f\u7684\u76f8\u540c\u7c7b\u578b\u6570\u636e\u7684\u96c6\u5408\uff0cSwift \u5b57\u5178\u4f1a\u5f3a\u5236\u68c0\u6d4b\u5143\u7d20\u7684\u7c7b\u578b\uff0c\u5982\u679c\u7c7b\u578b\u4e0d\u540c\u5219\u4f1a\u62a5\u9519\u3002<\/p>\n<p>Swift \u5b57\u5178\u6bcf\u4e2a\u503c\uff08value\uff09\u90fd\u5173\u8054\u552f\u4e00\u7684\u952e\uff08key\uff09\uff0c\u952e\u4f5c\u4e3a\u5b57\u5178\u4e2d\u7684\u8fd9\u4e2a\u503c\u6570\u636e\u7684\u6807\u8bc6\u7b26\u3002<\/p>\n<p>\u548c\u6570\u7ec4\u4e2d\u7684\u6570\u636e\u9879\u4e0d\u540c\uff0c\u5b57\u5178\u4e2d\u7684\u6570\u636e\u9879\u5e76\u6ca1\u6709\u5177\u4f53\u987a\u5e8f\u3002\u6211\u4eec\u5728\u9700\u8981\u901a\u8fc7\u6807\u8bc6\u7b26\uff08\u952e\uff09\u8bbf\u95ee\u6570\u636e\u7684\u65f6\u5019\u4f7f\u7528\u5b57\u5178\uff0c\u8fd9\u79cd\u65b9\u6cd5\u5f88\u5927\u7a0b\u5ea6\u4e0a\u548c\u6211\u4eec\u5728\u73b0\u5b9e\u4e16\u754c\u4e2d\u4f7f\u7528\u5b57\u5178\u67e5\u5b57\u4e49\u7684\u65b9\u6cd5\u4e00\u6837\u3002\n<\/p>\n<p>Swift \u5b57\u5178\u7684key\u6ca1\u6709\u7c7b\u578b\u9650\u5236\u53ef\u4ee5\u662f\u6574\u578b\u6216\u5b57\u7b26\u4e32\uff0c\u4f46\u5fc5\u987b\u662f\u552f\u4e00\u7684\u3002<\/p>\n<p>\u5982\u679c\u521b\u5efa\u4e00\u4e2a\u5b57\u5178\uff0c\u5e76\u8d4b\u503c\u7ed9\u4e00\u4e2a\u53d8\u91cf\uff0c\u5219\u521b\u5efa\u7684\u5b57\u5178\u5c31\u662f\u53ef\u4ee5\u4fee\u6539\u7684\u3002\u8fd9\u610f\u5473\u7740\u5728\u521b\u5efa\u5b57\u5178\u540e\uff0c\u53ef\u4ee5\u901a\u8fc7\u6dfb\u52a0\u3001\u5220\u9664\u3001\u4fee\u6539\u7684\u65b9\u5f0f\u6539\u53d8\u5b57\u5178\u91cc\u7684\u9879\u76ee\u3002\u5982\u679c\u5c06\u4e00\u4e2a\u5b57\u5178\u8d4b\u503c\u7ed9\u5e38\u91cf\uff0c\u5b57\u5178\u5c31\u4e0d\u53ef\u4fee\u6539\uff0c\u5e76\u4e14\u5b57\u5178\u7684\u5927\u5c0f\u548c\u5185\u5bb9\u90fd\u4e0d\u53ef\u4ee5\u4fee\u6539\u3002<\/p>\n<hr>\n<h2>\u521b\u5efa\u5b57\u5178<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\u6765\u521b\u5efa\u4e00\u4e2a\u7279\u5b9a\u7c7b\u578b\u7684\u7a7a\u5b57\u5178\uff1a<\/p>\n<pre>\nvar someDict =  [KeyType: ValueType]()\n<\/pre>\n<p>\u4ee5\u4e0b\u662f\u521b\u5efa\u4e00\u4e2a\u7a7a\u5b57\u5178\uff0c\u952e\u7684\u7c7b\u578b\u4e3a Int\uff0c\u503c\u7684\u7c7b\u578b\u4e3a String \u7684\u7b80\u5355\u8bed\u6cd5\uff1a<\/p>\n<pre>\nvar someDict = [Int: String]()\n<\/pre>\n<p>\u4ee5\u4e0b\u4e3a\u521b\u5efa\u4e00\u4e2a\u5b57\u5178\u7684\u5b9e\u4f8b\uff1a<\/p>\n<pre>\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n<\/pre>\n<hr>\n<h2>\u8bbf\u95ee\u5b57\u5178<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u6839\u636e\u5b57\u5178\u7684\u7d22\u5f15\u6765\u8bbf\u95ee\u6570\u7ec4\u7684\u5143\u7d20\uff0c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre>\nvar someVar = someDict[key]\n<\/pre>\n<p>\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4ee5\u4e0b\u5b9e\u4f8b\u6765\u5b66\u4e60\u5982\u4f55\u521b\u5efa\uff0c\u521d\u59cb\u5316\uff0c\u8bbf\u95ee\u5b57\u5178:<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nvar someVar = someDict[1]\n\nprint( \"key = 1 \u7684\u503c\u4e3a \\(someVar)\" )\nprint( \"key = 2 \u7684\u503c\u4e3a \\(someDict[2])\" )\nprint( \"key = 3 \u7684\u503c\u4e3a \\(someDict[3])\" )\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nkey = 1 \u7684\u503c\u4e3a Optional(\"One\")\nkey = 2 \u7684\u503c\u4e3a Optional(\"Two\")\nkey = 3 \u7684\u503c\u4e3a Optional(\"Three\")\n<\/pre>\n<hr>\n<h2>\u4fee\u6539\u5b57\u5178<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 <b>updateValue(forKey:)<\/b> \u589e\u52a0\u6216\u66f4\u65b0\u5b57\u5178\u7684\u5185\u5bb9\u3002\u5982\u679c key \u4e0d\u5b58\u5728\uff0c\u5219\u6dfb\u52a0\u503c\uff0c\u5982\u679c\u5b58\u5728\u5219\u4fee\u6539 key \u5bf9\u5e94\u7684\u503c\u3002updateValue(_:forKey:)\u65b9\u6cd5\u8fd4\u56deOptional\u503c\u3002\u5b9e\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nvar oldVal = someDict.updateValue(\"One \u65b0\u7684\u503c\", forKey: 1)\n\nvar someVar = someDict[1]\n\nprint( \"key = 1 \u65e7\u7684\u503c \\(oldVal)\" )\nprint( \"key = 1 \u7684\u503c\u4e3a \\(someVar)\" )\nprint( \"key = 2 \u7684\u503c\u4e3a \\(someDict[2])\" )\nprint( \"key = 3 \u7684\u503c\u4e3a \\(someDict[3])\" )\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nkey = 1 \u65e7\u7684\u503c Optional(\"One\")\nkey = 1 \u7684\u503c\u4e3a Optional(\"One \u65b0\u7684\u503c\")\nkey = 2 \u7684\u503c\u4e3a Optional(\"Two\")\nkey = 3 \u7684\u503c\u4e3a Optional(\"Three\")\n<\/pre>\n<p>\u4f60\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6307\u5b9a\u7684 key \u6765\u4fee\u6539\u5b57\u5178\u7684\u503c\uff0c\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nvar oldVal = someDict[1]\nsomeDict[1] = \"One \u65b0\u7684\u503c\"\nvar someVar = someDict[1]\n\nprint( \"key = 1 \u65e7\u7684\u503c \\(oldVal)\" )\nprint( \"key = 1 \u7684\u503c\u4e3a \\(someVar)\" )\nprint( \"key = 2 \u7684\u503c\u4e3a \\(someDict[2])\" )\nprint( \"key = 3 \u7684\u503c\u4e3a \\(someDict[3])\" )\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nkey = 1 \u65e7\u7684\u503c Optional(\"One\")\nkey = 1 \u7684\u503c\u4e3a Optional(\"One \u65b0\u7684\u503c\")\nkey = 2 \u7684\u503c\u4e3a Optional(\"Two\")\nkey = 3 \u7684\u503c\u4e3a Optional(\"Three\")\n<\/pre>\n<hr>\n<h2>\u79fb\u9664 Key-Value \u5bf9<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 <b>removeValueForKey()<\/b> \u65b9\u6cd5\u6765\u79fb\u9664\u5b57\u5178 key-value \u5bf9\u3002\u5982\u679c key \u5b58\u5728\u8be5\u65b9\u6cd5\u8fd4\u56de\u79fb\u9664\u7684\u503c\uff0c\u5982\u679c\u4e0d\u5b58\u5728\u8fd4\u56de nil \u3002\u5b9e\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nvar removedValue = someDict.removeValue(forKey: 2)\n\nprint( \"key = 1 \u7684\u503c\u4e3a \\(someDict[1])\" )\nprint( \"key = 2 \u7684\u503c\u4e3a \\(someDict[2])\" )\nprint( \"key = 3 \u7684\u503c\u4e3a \\(someDict[3])\" )\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nkey = 1 \u7684\u503c\u4e3a Optional(\"One\")\nkey = 2 \u7684\u503c\u4e3a nil\nkey = 3 \u7684\u503c\u4e3a Optional(\"Three\")\n<\/pre>\n<p>\u4f60\u4e5f\u53ef\u4ee5\u901a\u8fc7\u6307\u5b9a\u952e\u7684\u503c\u4e3a nil \u6765\u79fb\u9664 key-value\uff08\u952e-\u503c\uff09\u5bf9\u3002\u5b9e\u4f8b\u5982\u4e0b:<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nsomeDict[2] = nil\n\nprint( \"key = 1 \u7684\u503c\u4e3a \\(someDict[1])\" )\nprint( \"key = 2 \u7684\u503c\u4e3a \\(someDict[2])\" )\nprint( \"key = 3 \u7684\u503c\u4e3a \\(someDict[3])\" )\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nkey = 1 \u7684\u503c\u4e3a Optional(\"One\")\nkey = 2 \u7684\u503c\u4e3a nil\nkey = 3 \u7684\u503c\u4e3a Optional(\"Three\")\n<\/pre>\n<hr>\n<h2>\u904d\u5386\u5b57\u5178<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528 <b>for-in<\/b> \u5faa\u73af\u6765\u904d\u5386\u67d0\u4e2a\u5b57\u5178\u4e2d\u7684\u952e\u503c\u5bf9\u3002\u5b9e\u4f8b\u5982\u4e0b:<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nfor (key, value) in someDict {\n   print(\"\u5b57\u5178 key \\(key) -  \u5b57\u5178 value \\(value)\")\n}\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n\u5b57\u5178 key 2 -  \u5b57\u5178 value Two\n\u5b57\u5178 key 3 -  \u5b57\u5178 value Three\n\u5b57\u5178 key 1 -  \u5b57\u5178 value One\n<\/pre>\n<p>\u6211\u4eec\u4e5f\u53ef\u4ee5\u4f7f\u7528enumerate()\u65b9\u6cd5\u6765\u8fdb\u884c\u5b57\u5178\u904d\u5386\uff0c\u8fd4\u56de\u7684\u662f\u5b57\u5178\u7684\u7d22\u5f15\u53ca (key, value) \u5bf9\uff0c\u5b9e\u4f8b\u5982\u4e0b:<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nfor (key, value) in someDict.enumerate() {\n    print(\"\u5b57\u5178 key \\(key) -  \u5b57\u5178 (key, value) \u5bf9 \\(value)\")\n}\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n\u5b57\u5178 key 0 -  \u5b57\u5178 (key, value) \u5bf9 (2, \"Two\")\n\u5b57\u5178 key 1 -  \u5b57\u5178 (key, value) \u5bf9 (3, \"Three\")\n\u5b57\u5178 key 2 -  \u5b57\u5178 (key, value) \u5bf9 (1, \"One\")\n<\/pre>\n<hr>\n<h2>\u5b57\u5178\u8f6c\u6362\u4e3a\u6570\u7ec4<\/h2>\n<p>\u4f60\u53ef\u4ee5\u63d0\u53d6\u5b57\u5178\u7684\u952e\u503c(key-value)\u5bf9\uff0c\u5e76\u8f6c\u6362\u4e3a\u72ec\u7acb\u7684\u6570\u7ec4\u3002\u5b9e\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>\nimport Cocoa\n\nvar someDict:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\n\nlet dictKeys = [Int](someDict.keys)\nlet dictValues = [String](someDict.values)\n\nprint(\"\u8f93\u51fa\u5b57\u5178\u7684\u952e(key)\")\n\nfor (key) in dictKeys {\n    print(\"\\(key)\")\n}\n\nprint(\"\u8f93\u51fa\u5b57\u5178\u7684\u503c(value)\")\n\nfor (value) in dictValues {\n    print(\"\\(value)\")\n}\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\n\u8f93\u51fa\u5b57\u5178\u7684\u952e(key)\n2\n3\n1\n\u8f93\u51fa\u5b57\u5178\u7684\u503c(value)\nTwo\nThree\nOne\n<\/pre>\n<hr>\n<h2>count \u5c5e\u6027<\/h2>\n<p>\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u53ea\u8bfb\u7684 <b>count<\/b> \u5c5e\u6027\u6765\u8ba1\u7b97\u5b57\u5178\u6709\u591a\u5c11\u4e2a\u952e\u503c\u5bf9\uff1a<\/p>\n<pre>\nimport Cocoa\n\nvar someDict1:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\nvar someDict2:[Int:String] = [4:\"Four\", 5:\"Five\"]\n\nprint(\"someDict1 \u542b\u6709 \\(someDict1.count) \u4e2a\u952e\u503c\u5bf9\")\nprint(\"someDict2 \u542b\u6709 \\(someDict2.count) \u4e2a\u952e\u503c\u5bf9\")\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nsomeDict1 \u542b\u6709 3 \u4e2a\u952e\u503c\u5bf9\nsomeDict2 \u542b\u6709 2 \u4e2a\u952e\u503c\u5bf9\n<\/pre>\n<hr>\n<h2>isEmpty \u5c5e\u6027<\/h2>\n<p>Y\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u53ea\u8bfb\u5c5e\u6027 <b>isEmpty<\/b> \u6765\u5224\u65ad\u5b57\u5178\u662f\u5426\u4e3a\u7a7a\uff0c\u8fd4\u56de\u5e03\u5c14\u503c:<\/p>\n<pre>\nimport Cocoa\n\nvar someDict1:[Int:String] = [1:\"One\", 2:\"Two\", 3:\"Three\"]\nvar someDict2:[Int:String] = [4:\"Four\", 5:\"Five\"]\nvar someDict3:[Int:String] = [Int:String]()\n\nprint(\"someDict1 = \\(someDict1.isEmpty)\")\nprint(\"someDict2 = \\(someDict2.isEmpty)\")\nprint(\"someDict3 = \\(someDict3.isEmpty)\")\n<\/pre>\n<p>\u4ee5\u4e0a\u7a0b\u5e8f\u6267\u884c\u8f93\u51fa\u7ed3\u679c\u4e3a\uff1a<\/p>\n<pre>\nsomeDict1 = false\nsomeDict2 = false\nsomeDict3 = true\n<\/pre>\n<\/p><\/div>\n<\/p><\/div>\n<span>","protected":false},"excerpt":{"rendered":"<p class=\"excerpt\"><span itemprop=\"description\">Swift \u5b57\u5178 Swift \u5b57\u5178\u7528\u6765\u5b58\u50a8\u65e0\u5e8f\u7684\u76f8\u540c\u7c7b\u578b\u6570\u636e\u7684\u96c6\u5408\uff0cSwift \u5b57\u5178\u4f1a\u5f3a\u5236&hellip;<\/span><\/p>\n<p class=\"more-link-p btn-align-right\"><a class=\"green zoom-btn\" href=\"https:\/\/www.puzi7.net\/?p=532\">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-532","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\/532","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=532"}],"version-history":[{"count":0,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=\/wp\/v2\/posts\/532\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=532"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=532"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.puzi7.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}