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  • javascript变量,类型 第9节

    1、变量,数据类型

    <html>
    <head>
        <title>变量</title>
    </head>
    <body>
        <h3>变量 数据类型</h3>
        <script type="text/javascript">
            var i = 10;
            var k = 20;
            var d = new Date();
            document.write("i = " + i + "<br/>");
            document.write("d = " + d + "<br/>");
            i = new Object();
            document.write("i = " + i + "<br/>");
            i = new Array(10,20,30);
            document.write("i = " + i + "<br/>");
            j = k +20;
            document.write("j = " + j + "<br/>");
            var name = '张三';//字符串不区分",'
            document.write("name = " + name + "<br/>");
            var sex = '男';
            document.write("sex = " + sex + "<br/>");
            var married= false;
            var test;
            document.write("test = " + test + "<br/>");
            test = null;
            document.write("test = " + test + "<br/>");
            var obj = new Object();
            document.write("obj = " + obj + "<br/>");
        </script>
      <h3>2.检测变量的数据类型</h3>
      <script type="text/javascript">
        document.write("obj的类型 " + (typeof obj) + "<br/>");
        document.write("test:" + (typeof obj) + "<br/>");
        document.write("name 的类型" + (typeof name) +"<br/>");
        document.write("sex 的类型" + (typeof sex) + "<br/>");
        document.write("j :" + (typeof j) +"<br/>");
        document.write("married " + (typeof married ) + "<br/>");
        document.write("i 的类型 " + (typeof i) + "<br/>");
        document.write("i:" , i instanceof Array,"<br/>");
        document.write("i:", i instanceof Date,"<br/>");
      </script>
      <h3>3、运算符</h3>
      <script type="text/javascript">
        var a = 5;
        var b = 3;
        document.write("5 /3 = ",5/3,"<br/>");
        document.write("8 / 2 = ",8/2,"<br/>");
      </script>
    </body>
    </html>

     结果:

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  • 原文地址:https://www.cnblogs.com/feilongblog/p/4588853.html
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