localStorage 获取长度和值

    for(var i=localStorage.length - 1 ; i >=0; i--){  
                console.log("log:"+localStorage.key(i));  
                  console.log('第'+ (i+1) +'条数据的键值为：' + localStorage.key(i) +'，数据为：' + localStorage.getItem(localStorage.key(i)));  
                   }