丢点小东西

1.   判断一年多少天

    function getTotalDaysOfYear(arg) {
        var year = parseInt(arg);
        var check4 = (0 == (year % 4));            //判断年份是否能被4整除
        var check100 = (0 == (year % 100));          //判断年份是否能被100整除
        var check400 = (0 == (year % 400));         //判断年份是否能被400整除

        if((check4 && !check100) || check400) {
            return 366;
        } else {
            return 365;
        }
    }

2.  图片加载失败触发error事件

<img width="30" height="30" src="xxx.jpg" onerror="imgNotfound(this);" />
<script>
  window.imgNotfound = function (img) {
      var src = 'new.jpg';
      img.src = src;
      img.onerror = null;
  };
</script>