JS 动态判断PC和手机浏览器实现代码

<script>
var browser={ 
versions:function(){  
var u = navigator.userAgent, app = navigator.appVersion;  
return {  
trident: u.indexOf('Trident') > -1, //IE内核  
presto: u.indexOf('Presto') > -1, //opera内核  
webKit: u.indexOf('AppleWebKit') > -1, //苹果、谷歌内核  
gecko: u.indexOf('Gecko') > -1 && u.indexOf('KHTML') == -1, //火狐内核  
mobile: !!u.match(/AppleWebKit.*Mobile.*/)||!!u.match(/AppleWebKit/), //是否为移动终端  
ios: !!u.match(/\(i[^;]+;( U;)" 是否为移动终端: "+browser.versions.mobile);
document.writeln(" ios终端: "+browser.versions.ios);
document.writeln(" android终端: "+browser.versions.android);
document.writeln(" 是否为iPhone: "+browser.versions.iPhone);
document.writeln(" 是否iPad: "+browser.versions.iPad);
document.writeln(navigator.userAgent); 
</script>