es6对象的扩展底层实现____ObjectKeys_综合

Object.keys的用法：

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<head><meta charset="UTF-8"><title>Object.keys</title>
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<h1>Object.keys返回一个数组，包括对象自身的（不含继承的）所有可枚举属性</h1>
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<script>class Student{constructor(name, age) {this.name=name;this.age=age;}}var stu = new Student("小刚",18);var keys=Object.keys(stu);console.log(keys.toString());
</script>
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Object.keys的底层实现

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>ObjectKeys</title>
</head>
<body></body>
<script>class Student{constructor(name, age) {this.name=name;this.age=age;}}Student.prototype.ObjectKeys = function () {var buffer = [];for(key in this) {buffer.push(key);}return buffer;}var stu = new Student("小刚",18);let keys = stu.ObjectKeys();console.log(keys.toString());
</script>
</html>