获取页面的编码格式

function getCharset(){
    var paras = document.getElementsByTagName("meta");//js获取所有meta
    //var paras=$('meta');//jq获取
    var regGbk=/(gbk|GB2312)/i;//适配gbk或者gbxxxx
    var regUtf=/(utf8|utf-8)/i;//匹配utf-8编码的两种写法
    var thisCharset='';
    for(var i=0;i<paras.length;i++){
        var content =paras[i].getAttribute("content");
        var httpEquiv = paras[i].getAttribute("http-equiv");
        var charset=paras[i].getAttribute("charset");
        if(httpEquiv&&content.match(regGbk)){//gbk
            var charset=paras[i].getAttribute("content");
            thisCharset='gbk';
        }else if(charset&&charset.match(regUtf)){//utf-8
            var charset=paras[i].getAttribute("charset");
            thisCharset='utf-8';
        }
    }
    return {'charset':thisCharset};    
}
getCharset();
//{charset: "utf-8"}