js 支持的数据类型

<script>
   var a =12;
   a = -12
   a = 12.4
   a =.23e2 //=>23
   a = 2e3 //=>2000
   a = 3E-2 //==>0.03   
</script>

1 <script>
2     var a = 0xab //=>171
3     a = 0XAAA  //=>2730    
4 </script>

1 <script>
2     var a = 0123   //=>83
3     a = 0111111   //=>37449    
4 </script>

 1 <script>
 2     var a = 1.79e310
 3     alert(a) //==>infinity
 4     a = -1.79e310
 5     alert(a)  //=>-infinity
 6     var b = 12
 7     //NaN 表示not a number 不是一个数字
 8     alert(isNaN(b))  //=>false
 9     //NaN不能与自身比较
10     alert(NaN == NaN) //=>false
11 </script>