js使用cookie存值和取值

1.cookie中存值

function setCookie (name, value) {
  if (value) {
    var Days = 365;
    var exp = new Date();
    exp.setTime(exp.getTime() + Days * 24 * 60 * 60 * 1000);
    document.cookie = name + '=' + escape(value) + ';expires=' + exp.toGMTString();
  }
}

2.cookie中取值

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

3.清除指定cookie

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

4.清除全部cookie

function clearCookie () {
  var keys = document.cookie.match(/[^ =;]+(?==)/g)
  if (keys) {
    for (var i = keys.length; i--;) {
      document.cookie = keys[i] + '=0;expires=' + new Date(0).toUTCString()
    }
  }
}

cookie中特殊字符处理：（分号（;）、逗号（,）、等号（=）以及空格）
js对文字进行编码涉及3个函数：

编码：escape,encodeURI,encodeURIComponent，
解码：unescape,decodeURI,decodeURIComponent