{"id":121,"date":"2016-07-12T19:49:55","date_gmt":"2016-07-12T11:49:55","guid":{"rendered":"http:\/\/120.27.50.22\/wordpress\/?p=121"},"modified":"2016-07-12T19:49:55","modified_gmt":"2016-07-12T11:49:55","slug":"javascript%e4%b8%ad%e6%a3%80%e6%b5%8b%e5%8f%98%e9%87%8f%e6%98%af%e5%90%a6%e5%ad%98%e5%9c%a8","status":"publish","type":"post","link":"http:\/\/www.homconnect.cn\/?p=121","title":{"rendered":"JavaScript\u4e2d\u68c0\u6d4b\u53d8\u91cf\u662f\u5426\u5b58\u5728"},"content":{"rendered":"

\u5728\u7f16\u5199JavaScript\u7a0b\u5e8f\u65f6\u5f80\u5f80\u9700\u8981\u68c0\u6d4b\u67d0\u4e00\u53d8\u91cf\u662f\u5426\u5b58\u5728\uff0c\u8fd9\u662f\u4e00\u4ef6\u975e\u5e38\u7b80\u5355\u7684\u5de5\u4f5c\uff0c\u4f46\u5982\u679c\u4e0d\u7ec6\u5fc3\u4e5f\u4f1a\u9047\u5230\u4e00\u4e9b\u95ee\u9898\u3002\u4e3b\u8981\u6709\u4e00\u4e9b\u51e0\u70b9\uff1a<\/p>\n

1\u3001\u666e\u901a\u53d8\u91cf<\/p>\n

<script\u00a0type=”text\/javascript”>
\nif(variable){
\nalert(‘rain\u00a0man’);
\n}
\n<\/script><\/p><\/blockquote>\n

\u8fd9\u65f6\u4f1a\u51fa\u73b0\u2018variable is not defined\u2019\u7684\u9519\u8bef\uff0c\u5982\u679c\u6539\u6210\u4e0b\u9762\u5c31\u4f1a\u5f39\u51fa\u9884\u671f\u7684\u5bf9\u8bdd\u6846\uff1a<\/p>\n

<script\u00a0type=”text\/javascript”>
\nif(\u00a0typeof\u00a0variable\u00a0==\u00a0‘undefined’\u00a0){
\nalert(‘rain\u00a0man’);
\n}
\n<\/script><\/p><\/blockquote>\n

<\/p>\n

2\u3001 \u5bf9\u8c61\u7684\u5c5e\u6027<\/p>\n

<script\u00a0type=”text\/javascript”>
\nvar\u00a0two\u00a0=\u00a0{};
\nif(two.b){
\nalert(‘rain man’);
\n}
\nif(\u00a0window.addEventListener\u00a0){
\nalert(‘This\u00a0is\u00a0not\u00a0IE!’);
\n}
\n<\/script><\/p><\/blockquote>\n

\u5bf9\u4e8e\u68c0\u6d4b\u5bf9\u8c61\u7684\u5c5e\u6027\u5219\u4e0d\u5fc5\u4f7f\u7528 typeof \u3002<\/p>\n

3\u3001\u5728\u7ed9\u5bf9\u8c61\u6dfb\u52a0\u5c5e\u6027\u65f6\uff0c\u4e5f\u4f1a\u9047\u5230\u7c7b\u4f3c\u7684\u95ee\u9898\u3002<\/p>\n

<script\u00a0type=”text\/javascript”>
\nvar\u00a0obj\u00a0=\u00a0{};
\nobj.property.number\u00a0=\u00a02;\u00a0\u00a0\u00a0\u00a0\/\/\u8fd9\u65f6\u4f1a\u51fa\u73b0\u00a0‘obj.property\u00a0is\u00a0undefined’\u00a0\u7684\u9519\u8bef<\/p>\n

\/**
\n*\u00a0\u00a0\u00a0\u00a0\u4e0b\u9762\u8fd9\u79cd\u60c5\u51b5\u867d\u7136\u6ca1\u6709\u51fa\u73b0\u8bed\u6cd5\u9519\u8bef,\u4f46\u5b9e\u9645\u4e0a\u5df2\u7ecf\u51fa\u73b0\u4e86\u9519\u8bef.
\n*\u00a0\u00a0\u00a0\u00a0\u5c5e\u6027\u662f\u590d\u5408\u578b\u53d8\u91cf\u6240\u7279\u6709\u7684,\u800cobj.property\u662f\u6570\u503c\u578b\u53d8\u91cf,\u4e0d\u80fd\u542b\u6709\u5c5e\u6027.
\n*\/
\nvar\u00a0obj\u00a0=\u00a0{};
\nobj.property\u00a0=\u00a02\u00a0;
\nobj.property.number\u00a0=\u00a03;
\n<\/script><\/p><\/blockquote>\n

FROM:\u00a0http:\/\/www.cnblogs.com\/rainman\/archive\/2009\/02\/10\/1387733.htm<\/p>\n","protected":false},"excerpt":{"rendered":"

\u5728\u7f16\u5199JavaScript\u7a0b\u5e8f\u65f6\u5f80\u5f80\u9700\u8981\u68c0\u6d4b\u67d0\u4e00\u53d8\u91cf\u662f\u5426\u5b58\u5728\uff0c\u8fd9\u662f\u4e00\u4ef6\u975e\u5e38\u7b80\u5355\u7684\u5de5\u4f5c\uff0c\u4f46\u5982\u679c\u4e0d\u7ec6\u5fc3\u4e5f\u4f1a\u9047\u5230\u4e00\u4e9b … \u7ee7\u7eed\u9605\u8bfb\u201cJavaScript\u4e2d\u68c0\u6d4b\u53d8\u91cf\u662f\u5426\u5b58\u5728\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":[30],"tags":[],"_links":{"self":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/121"}],"collection":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=121"}],"version-history":[{"count":1,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/121\/revisions"}],"predecessor-version":[{"id":122,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=\/wp\/v2\/posts\/121\/revisions\/122"}],"wp:attachment":[{"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=121"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=121"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.homconnect.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=121"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}