lovecoding
/
web0715


			
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // Function Array Object ...

        var str = "hello";
        var num = 10;
        var boo = true;
        var arr = [1,2];
        var obj = {a:1};
        var foo = function(){console.log(1)};
        var und = undefined;
        var nu = null;

        // 方法一
        // console.log( typeof str );
        // console.log( typeof num);
        // console.log( typeof boo);
        // console.log( typeof arr);
        // console.log( typeof obj);
        // console.log( typeof foo);
        // console.log( typeof und);
        // console.log( typeof nu);

        // 方法二
        // instanceof 只能判断 object array function
        // console.log( arr instanceof Array );
        // console.log( obj instanceof Object );
        // console.log( str instanceof String );
        // console.log( foo instanceof Function );

        // 方法三
        // console.log(arr.constructor == Array)
        // console.log(str.constructor == String);
        // console.log(num.constructor == Number);
        // console.log(foo.constructor == Function);
        // console.log(obj.constructor == Object);
        // console.log(boo.constructor == Boolean);

        // 方法四
        // console.log( Object.prototype.toString.call(und) );
        // console.log( Object.prototype.toString.call(nu) );
        // console.log( Object.prototype.toString.call(str) );
        // console.log( Object.prototype.toString.call(num) );
        // console.log( Object.prototype.toString.call(foo) );
        // console.log( Object.prototype.toString.call(boo) );
        // console.log( Object.prototype.toString.call(arr) );
        // console.log( Object.prototype.toString.call(obj) );


    </script>
</body>
</html>