​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript Object.keys()</h1>
​
<p>本例列出一个对象的可枚举属性。</p>
​
<p id="demo"></p>
​
<script>
// 创建对象：
const person = {
  firstName: "Bill",
  lastName: "Gates",
  language: "EN"
}
​
// 更改属性
Object.defineProperty(person, "language", {enumerable:false});
​
// 显示属性
document.getElementById("demo").innerHTML = Object.keys(person);
</script>
​
</body>
</html>
​