js清空cookie

function setCookie(name,value){
    var Days = 30;
    var exp = new Date();
    exp.setTime(exp.getTime() + Days*24*60*60*1000);
    document.cookie = name + "="+ escape (value) + ";expires=" + exp.toGMTString();
}

function getCookie(name){
    var arr,reg=new RegExp("(^| )"+name+"=([^;]*)(;|$)");
    if(arr=document.cookie.match(reg)){
        return unescape(arr[2]);
    }else{
        return null;
    }
}

function delCookie(name){
    var exp = new Date();
    exp.setTime(exp.getTime() - 1);
    var cval=getCookie(name);
    if(cval!=null){
        document.cookie= name + "="+cval+";expires="+exp.toGMTString();
    } 
}

        
　　　　　　 function clearAllCookie() {
                var date=new Date();
                date.setTime(date.getTime()-10000);
                var keys=document.cookie.match(/[^ =;]+(?=\=)/g);
                console.log("需要删除的cookie名字："+keys);
                if (keys) {
                    for (var i =  keys.length; i--;)
                      document.cookie=keys[i]+"=0; expire="+date.toGMTString()+"; path=/";
                }
            }