javascript通过navigator.userAgent识别各种浏览器

unction validBrowser(){ 
var u_agent = navigator.userAgent; 
var browser_name=‘Failed to identify the browser‘; 
if(u_agent.indexOf(‘Firefox‘)>-1){ 
browser_name=‘Firefox‘; 
}else if(u_agent.indexOf(‘Chrome‘)>-1){ 
browser_name=‘Chrome‘; 
}else if(u_agent.indexOf(‘Trident‘)>-1&&u_agent.indexOf(‘rv:11‘)>-1){ 
browser_name=‘IE11‘; 
}else if(u_agent.indexOf(‘MSIE‘)>-1&&u_agent.indexOf(‘Trident‘)>-1){ 
browser_name=‘IE(8-10)‘; 
}else if(u_agent.indexOf(‘MSIE‘)>-1){ 
browser_name=‘IE(6-7)‘; 
}else if(u_agent.indexOf(‘Opera‘)>-1){ 
browser_name=‘Opera‘; 
}else{ 
browser_name+=‘,info:‘+u_agent; 
} 
document.write(‘browser_name:‘+browser_name+‘<br>‘); 
document.write(‘u_agent:‘+u_agent+‘<br>‘); 
} 

if (window.navigator.userAgent.indexOf(‘compatible‘) != -1) {
alert(‘360兼容模式‘);
}
if(window.navigator.userAgent.indexOf(‘AppleWebKit‘) != -1) {
alert(‘360极速模式‘);
}