检测 localStorage 最大写入值

check_localStorage_max_size.js

(function() {
  //判断浏览器是否支持localStorage
   if(!window.localStorage) {
   console.log('当前浏览器不支持localStorage!');
   return false;
   }    
   var test = '0123456789';
   //递归  加到10kb
   var add = function(num) {
     num += num;
     if(num.length == 10240) {
       test = num;
       return;
     }
     add(num);
   }
   
   add(test);
   
   var sum = test;
   var show = setInterval(function(){
      //每次增加10kb
      sum += test;
      try {
       window.localStorage.removeItem('test');
       window.localStorage.setItem('test', sum);
	   //控制台输出当前大小（kb）
       console.log(sum.length / 1024 + 'KB');
      } catch(e) {
	  //如果大小超出范围setItem会报异常 这时就是超出最大限制
       console.log(sum.length / 1024 + 'KB超出最大限制');
	   //清除定时
       clearInterval(show);
      }
   }, 0.1)
 })()