封装cookie

设置cookie

function setCookie( key , value ,day ){

      if( day ){

            var now = new Date();

            now.setDate( now.getDate() + day );

            document.cookie = key +"=" + value + ";expires="+now;

      }else{

            document.cookie = key +"=" + value;

      }

}

 

获取cookie  "username"  "password"

function getCookie(key){//tel

      var str = document.cookie;

      if( str ){   如果cookie存在  根据key取对应的值

            str = str.replace( /s/g ,"");   去掉cookie中的空格

            var arr = str.split(";");   将字符串拆成数组

            for( var i = 0 ; i < arr.length ; i++ ){

                  var item = arr[i].split("=");

                  if( item[0] == key ){

                        return item[1];

                  }

            }

            循环结束后 如果没有找到对应的key   返回""

            return "";

      }

      cookie 不存在  返回""

      return "";

}

 

删除cookie   将key的值设置为""

function removeCookie( key ){

      setCookie( key , "" );

}