{"id":1174,"date":"2012-04-08T13:29:35","date_gmt":"2012-04-08T05:29:35","guid":{"rendered":"http:\/\/leegorous.net\/blog\/?p=1174"},"modified":"2012-04-08T15:35:48","modified_gmt":"2012-04-08T07:35:48","slug":"javascript-object","status":"publish","type":"post","link":"http:\/\/leegorous.net\/blog\/2012\/04\/08\/javascript-object\/","title":{"rendered":"Javascript Object \u6742\u8c08"},"content":{"rendered":"

\u770b\u5230 \u4e00\u4e2a\u8bba\u575b\u5e16\u5b50<\/a> \u95ee\u5230\uff1a(\u7c7b\u4f3c\u4e0b\u9762\u7684\u4ee3\u7801) <\/p>\n

\r\nvar arr = [1, 2, 3];\r\narr.a = 'a';\r\narr.b = 'b';\r\n<\/pre>\n
\u4e3a\u4ec0\u4e48\u53ef\u4ee5\u8fd9\u6837\u5199\uff1farr \u81ea\u8eab\u5230\u5e95\u662f\u4ec0\u4e48\uff1f<\/p>\n
\u539f\u56e0\u5176\u5b9e\u5f88\u7b80\u5355\uff0c\u56e0\u4e3a js \u91cc\u4e00\u5207\u90fd\u662f\u5bf9\u8c61\uff0carray \u4e5f\u662f object\uff0c\u6240\u4ee5\u5b83\u5c31\u80fd\u505a\u6240\u6709 object \u80fd\u505a\u7684\u4e8b\u60c5\uff0c\u6bd4\u5982\uff0c\u7ed9\u5b83\u52a0\u4e2a\u5c5e\u6027 a<\/em>\u3002<\/p>\n
\u5982\u679c Array<\/a> \u80fd\u90a3\u4e48\u641e\uff0cBoolean<\/a>\uff0cDate<\/a>, Function<\/a>, Number<\/a>\uff0cRegExp<\/a>\uff0cString<\/a> \u4e5f\u53ef\u4ee5\u5c31\u4e0d\u8db3\u4e3a\u5947\u4e86\u3002<\/p>\n
\r\nfunction toStr(obj) {\r\n  return Object.prototype.toString.call(obj); \r\n}\r\n\r\nfunction addAttr(arr) {\r\n  for(var i = arr.length-1; i >= 0; i--) {\r\n    arr[i].attr = toStr(arr[i]);\r\n  }\r\n  return arr;\r\n}\r\n\r\nfunction checkAttr(arr) {\r\n  for(var i = 0; i < arr.length; i++) {\r\n    console.log(typeof arr[i], arr[i].attr);\r\n  }\r\n}\r\n\r\nvar arr = [\r\n    new Boolean(false), \r\n    new Date(), \r\n    new Function(), \r\n    new RegExp('\\\\w+'), \r\n    new Number(1.0), \r\n    new String('str')];\r\ncheckAttr(addAttr(arr));\r\n\r\n\/** output >>\r\nobject [object Boolean]\r\nobject [object Date]\r\nfunction [object Function]\r\nobject [object RegExp]\r\nobject [object Number]\r\nobject [object String]\r\n*\/<\/pre>\n
\u7ec6\u5fc3\u7684\u4eba\u4f1a\u53d1\u73b0\u4e0a\u9762\u90fd\u662f\u4f7f\u7528 new \u6784\u9020\u7684\u5bf9\u8c61\uff0c\u5982\u679c\u6362\u6210\u662f\u5b57\u9762\u65b9\u5f0f (literal) \u5b9a\u4e49\u7684\u539f\u751f\u7c7b\u578b (primitive) \u53c8\u4f1a\u662f\u5982\u4f55\u5462\uff1f<\/p>\n
\r\nvar arr = [false, 1.0, 'str'];\r\ncheckAttr(addAttr(arr));\r\n\/** output >>\r\nboolean undefined\r\nnumber undefined\r\nstring undefined\r\n*\/\r\n<\/pre>\n
\u5728 js \u91cc\u4e00\u5207\u90fd\u662f\u5bf9\u8c61\uff0c\u4f46\u539f\u751f\u7c7b\u578b\u5bf9\u8c61 (boolean, number, string) \u4e0e\u975e\u539f\u751f\u7c7b\u578b\u5bf9\u8c61\u8fd8\u662f\u6709\u533a\u522b\u7684\u3002\u524d\u8005\u53ef\u80fd\u79f0\u4e4b\u4e3a \u539f\u751f\u6570\u636e (primitive data)<\/strong> \u4f1a\u66f4\u52a0\u9002\u5408\u3002\u800c\u5728\u9700\u8981\u7684\u65f6\u5019\uff08\u8bbf\u95ee\u5c5e\u6027\uff0c\u8c03\u7528\u65b9\u6cd5\uff09\uff0cjs \u4f1a\u81ea\u52a8\u5c06\u539f\u751f\u6570\u636e\u5c01\u88c5\u6210\u5bf9\u8c61\u7136\u540e\u518d\u8fdb\u884c\u5904\u7406 [\u53c2\u8003<\/a>]\u3002\u800c\u539f\u751f\u6570\u636e\u7684\u5b58\u5728\uff0c\u662f\u56e0\u4e3a\u6027\u80fd\u7684\u539f\u56e0 [\u53c2\u8003<\/a>]\u3002\u6240\u4ee5 js \u91cc\u4e00\u5207\u90fd\u662f\u5bf9\u8c61\u662f\u5bf9\u4f7f\u7528\u8005\u800c\u8a00\u3002<\/p>\n
\u867d\u7136\uff0c\u6211\u4eec\u53ef\u4ee5\u7ed9\u6570\u7ec4\u5bf9\u8c61\u6dfb\u52a0\u5c5e\u6027\uff0c\u4f46\u5e76\u4e0d\u5efa\u8bae\u90a3\u4e48\u505a\uff0c\u539f\u56e0\u662f Array \u5e76\u4e0d\u9884\u671f\u88ab\u5f53\u4f5c key\/value \u5f62\u5f0f\u7684\u5bf9\u8c61\u6765\u4f7f\u7528<\/a>\u3002\u60c5\u51b5\u653e\u5230 Boolean, Number, String \u7b49\u5bf9\u8c61\u4e0a\u662f\u4e00\u6837\u7684\u3002<\/p>\n
\u9664\u975e\uff0c\u4e0d\u7ed9\u5b9a\u8fd9\u4e2a\u9884\u671f\uff0c\u6216\u8005\u6539\u53d8\u8fd9\u4e2a\u9884\u671f\u3002<\/p>\n
\u6bd4\u5982\uff0c\u4f7f\u7528 jQuery\uff0c\u5728\u6267\u884c $(selector) \u8fd4\u56de\u7684\u662f\u4e00\u4e2a jQuery \u5bf9\u8c61\uff0c\u8fd9\u4e2a\u5bf9\u8c61\u53ef\u4ee5\u6267\u884c jQuery.fn \u4e0a\u9762\u7684\u6240\u6709\u65b9\u6cd5\uff0c\u5e76\u4e14\u53ef\u4ee5\u50cf\u8bbf\u95ee\u4e00\u4e2a\u6570\u7ec4\u90a3\u6837\u8bbf\u95ee\u91cc\u9762\u6240\u5305\u542b\u7684\u6570\u636e\u8282\u70b9\u3002\u4e0b\u9762\u662f jQuery \u4e2d \/src\/core.js<\/a> \u7684\u4e00\u4e9b\u6e90\u4ee3\u7801\u7247\u65ad\uff1a<\/p>\n
\r\njQuery.fn = jQuery.prototype = {\r\n     constructor: jQuery,\r\n     init: function( selector, context, rootjQuery ) {\r\n       \/\/ ...\r\n       return jQuery.merge( this, selector );\r\n     },\r\n    \r\n     \/\/ For internal use only.\r\n     \/\/ Behaves like an Array's method, not like a jQuery method.\r\n     push: push,\r\n     sort: [].sort,\r\n     splice: [].splice\r\n};\r\n\r\n\/\/ Give the init function the jQuery prototype for later instantiation\r\njQuery.fn.init.prototype = jQuery.fn;\r\n<\/pre>\n
\u901a\u8fc7\u67e5\u8be2\u8fc7\u6ee4\u4e4b\u540e\uff0c\u4eba\u4eec\u4f1a\u9884\u671f\u5f97\u5230\u7684\u662f\u4e00\u4e2a\u8282\u70b9\u6570\u7ec4\uff0c\u4f46 jQuery \u5e76\u6ca1\u6709\u7b80\u5355\u7684\u8fd4\u56de\u90a3\u4e2a\u6570\u7ec4\uff08\u5982\u679c\u771f\u662f\u90a3\u6837\uff0c\u540e\u9762\u5c31\u6ca1\u620f\u4e86\uff09\uff0c\u800c\u662f\u5c06\u67e5\u8be2\u7684\u7ed3\u679c\u5408\u5e76\u5230\u4e00\u4e2a jQuery \u7c7b\u578b\u7684\u5bf9\u8c61\u4e0a\u7136\u540e\u8fd4\u56de\u3002\u4e5f\u5c31\u662f\u4e0a\u9762\u4ee3\u7801\u4e2d constructor \u548c init \u7684\u90e8\u5206\u3002\u540e\u9762\u6dfb\u52a0\u5230 jQuery.fn \u7684 push, sort, splice \u90fd\u662f Array prototype \u4e0a\u7684\u65b9\u6cd5\uff0c\u76ee\u7684\u5c31\u662f\u4f7f\u8fd9\u4e2a\u5bf9\u8c61\u53ef\u4ee5\u50cf\u4e2a Array \u4e00\u6837\u64cd\u4f5c\uff0c\u867d\u7136\u6ce8\u91ca\u91cc\u8bf4\u7684\u662f\u4ec5\u4f9b\u5185\u90e8\u4f7f\u7528\u3002<\/p>\n
\u5728 Array object \u4e0a\u6dfb\u52a0\u5c5e\u6027\u6570\u636e\u7b97\u4e0d\u7b26\u5408\u9884\u671f\u3002\u4f46\u5982\u679c\u53cd\u8fc7\u6765\uff0c\u5c06\u4e00\u4e2a object \u6a21\u62df\u6210 Array\uff0c\u8fd9\u6837\u5c31\u6ca1\u6709\u4e86\u539f\u6765\u7684\u201c\u9884\u671f\u201d\u7684\u969c\u788d\uff0c\u901a\u8fc7\u7ed9\u51fa\u65b0\u7684\u9884\u671f\uff0c\u6765\u8868\u8fbe\u7a0b\u5e8f\u7684\u8bbe\u8ba1\u76ee\u7684\u3002<\/p>\n
\u6211\u5728\u5404\u79cd\u573a\u5408\uff0c\u65e0\u6570\u6b21\u542c\u89c1\u4eba\u4eec\u76db\u8d5e jQuery \u662f\u5982\u4f55\u597d\u7528\uff0c\u91cc\u9762\u4e5f\u662f\u6709\u51e0\u5206 JavaScript Object \u7684\u529f\u52b3\u7684\uff0c\u4f46\u66f4\u91cd\u8981\u7684\u662f\uff0c\u8bbe\u8ba1\u8005\u6709\u624e\u5b9e\u7684\u57fa\u672c\u529f\uff0c\u65e2\u5c0a\u91cd\u4f20\u7edf\uff0c\u53c8\u6562\u4e8e\u7a81\u7834\u3002<\/p>\n
Object<\/a> \u662f\u5982\u6b64\u7684\u7b80\u5355\u800c\u7075\u6d3b\u3002\u5b83\u53ef\u4ee5\u5305\u542b\u5c5e\u6027\u4e0e\u65b9\u6cd5\uff0c\u5f53\u6210\u5bf9\u8c61\u6765\u4f7f\u7528\uff1b\u53ef\u4ee5\u4ee5 maps \u6216\u8005 key\/value pairs \u7684\u5f62\u5f0f\u4f5c\u4e3a\u6570\u636e\u4f7f\u7528\u3002\u5b83\u662f\u5426\u8fd8\u6709\u4ec0\u4e48\u672a\u77e5\u9886\u57df\u7b49\u5f85\u4eba\u4eec\u53bb\u53d1\u6398\u5462\uff1f<\/p>\n
<\u53c2\u8003><\/em>
\nJavaScript Coercion Demystified<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u770b\u5230 \u4e00\u4e2a\u8bba\u575b\u5e16\u5b50 \u95ee\u5230\uff1a(\u7c7b\u4f3c\u4e0b\u9762\u7684\u4ee3\u7801) var arr = [1, 2, 3]; arr.a = &#0 … <\/p>\n
\u7ee7\u7eed\u9605\u8bfb\u201cJavascript Object \u6742\u8c08\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[102],"tags":[9],"_links":{"self":[{"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/posts\/1174"}],"collection":[{"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/comments?post=1174"}],"version-history":[{"count":8,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/posts\/1174\/revisions"}],"predecessor-version":[{"id":1181,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/posts\/1174\/revisions\/1181"}],"wp:attachment":[{"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/media?parent=1174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/categories?post=1174"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/leegorous.net\/blog\/wp-json\/wp\/v2\/tags?post=1174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}