javascript变量类型

变量类型

number 数字 整数 小数 负数
string 字符串
boolean 布尔值 true/false
undefined 未赋值的变量类型就是undefined
null 空引用

number
<body>
    <script>
        var a1 = 11;
        var a2 = 11.11;
        var a3 = -11;
        console.log(a1, typeof(a1));
        console.log(a2, typeof(a2));
        console.log(a3, typeof(a3));
    </script>
</body>

string
<body>
    <script>
        var a1 = "hello";
        var a2 = "11";
        console.log(a1, typeof(a1));
        console.log(a2, typeof(a2));
    </script>
</body>

boolean
<body>
    <script>
        var a1 = true;
        var a2 = false;
        console.log(a1, typeof(a1));
        console.log(a2, typeof(a2));
    </script>
</body>
undefined和null
<body>
    <script>
        var a1;
        var a2 = null;
        console.log(a1, typeof(a1));
        console.log(a2, typeof(a2));
    </script>
</body>

posted @ 2020-10-20 16:07  qqaazzhf  阅读(70)  评论(0)    收藏  举报