277 原型测试题

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>06_原型测试题</title>
</head>

<body>

    <script type="text/javascript">
        /*
                                  测试题1
                                   */
        function A() {

        }
        A.prototype.n = 1

        var b = new A()

        A.prototype = {
            n: 2,
            m: 3
        }

        var c = new A()
        console.log(b.n, b.m, c.n, c.m) // 1 undefined 2 3


        /*
         测试题2
         */
        function F() {}
        Object.prototype.a = function() {
            console.log('a()')
        }
        Function.prototype.b = function() {
            console.log('b()')
        }

        var f = new F()
        f.a(); // a()
        // f.b() // 报错，f.b is not a function
        F.a() // a() ,这里把F看成实例对象
        F.b() // b()
        console.log(f)
        console.log(Object.prototype)
        console.log(Function.prototype)  // ƒ () { [native code] }
    </script>
</body>

</html>
277 原型测试题

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