11_ for 练习 _ Math.sqrt 

  • <!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8" />
        <title>Is Prime Number? Better way.</title>
    </head>
    <body>
        <script type="text/javascript">
            var xNumber = +prompt("请输入一个大于1的数字：");
            var isPrimeNumber = true;
            
            if(xNumber>1 && xNumber != NaN)
            {
                for(i=2; i<Math.sqrt(xNumber); i++)
                {
                   if(xNumber%i==0)
                   {
                       isPrimeNumber = false;
                       break;
                   }
                }
            }
            if(isPrimeNumber)
            {
                document.write(xNumber+" is a Prime Number.");
            }
            else
            {
                document.write(xNumber+" is NOT a Prime Number.");
            }
        </script>
    </body>
</html>

     

posted @ 2018-09-20 20:52  耶梦加德  阅读(165)  评论(0)  编辑  收藏  举报