类型转换

 

    <script language="javascript" type="text/javascript">

        //boolean()强制转换,当参数为空字符串和null时，得到false

        document.write("强制转换<br />");

        document.write(Boolean('')+"<br />");

        document.write(Boolean(100)+"<br />");

        document.write(Boolean(null)+"<br />");

        document.write(Boolean(new Object())+"<br />");

        //转换

        var sColor="violet";

        document.write(sColor.length,"<br />");

        var bFound=false;

        document.write(bFound.toString(),"<br />");

        var iNum=10;

        document.write("10的二进制数为",iNum.toString(2),"<br />");

        document.write("10的八进制数为",iNum.toString(8),"<br />");

        document.write("10的十进制数为",iNum.toString(10),"<br />");

        //转换成数字

        function testFunction(){}

        document.write(Number(testFunction()),"<br />");

        document.write(Number("123.23"),"<br />");

        document.write(Number(false),"<br />");

        document.write(Number(true),"<br />");

        document.write(parseInt("58"), "<br />");

        document.write(parseFloat("56.6"), "<br />");

      //-------------------------输出结果---------------------------------

      //强制转换

      //false

      //true

      //false

      //true

      //6

      //false

      //10的二进制数为1010

      //10的八进制数为12

      //10的十进制数为10

      //NaN

      //123.23

      //0

      //1

      //58

      //56.6

    </script>