js中cookie操作

function getCookie(c_name){
    if (document.cookie.length>0){ 
        console.log(document.cookie);
        c_start=document.cookie.indexOf(c_name + "=");
        if (c_start!=-1){ 
            c_start=c_start + c_name.length+1; 
            c_end=document.cookie.indexOf(";",c_start);
            if (c_end==-1) c_end=document.cookie.length;
            return unescape(document.cookie.substring(c_start,c_end));
        } 
    }
    return "";
}

function setCookie(c_name,value,expiredays){
    var cookieStr = "";
    var exdate=new Date();
    exdate.setDate(exdate.getDate()+expiredays);
    document.cookie = c_name+ "=" +escape(value)+
    ((expiredays==null) ? "" : "; expires="+exdate.toGMTString())+";path=/";
}//由于cookie存在域的概念，且在这里要不区分域，获取cookie的值，所以在这里使用的是统一的路径 path=/ ；

function delete_cookie( name, path, domain ) {
  if( get_cookie( name ) ) {
    document.cookie = name + "=" +
      ((path) ? ";path="+path:"")+
      ((domain)?";domain="+domain:"") +
      ";expires=Thu, 01 Jan 1970 00:00:01 GMT";
  }
}

function delete_cookie( name ) {
  document.cookie = name + ‘=; expires=Thu, 01 Jan 1970 00:00:01 GMT;‘;
}

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