当前位置：网站首页>6. Data agent object Defineproperty method

6. Data agent object Defineproperty method

2022-07-03 19:39:00 【Shura MIUI】 

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
	</body>
</html>

<script>
	var number = 10;
	//1
	let person = {
    
		name: ' Zhang San ',
		sex: ' male '
	};
	// Defining attributes ,
	Object.defineProperty(person, 'age', {
    
		// value: 18,
		enumerable: false, // When enumerable by false when age Properties cannot be enumerated ,
		// writable:false,//false The attribute value cannot be modified 
		// configurable: false, //false Attributes cannot be deleted and defined set Method 
		// When accessing age Called when value get Method , When defining get When the method is used ,value and writable Don't define 
		// get: function() {
    
		// return number;
		// },
		//  When modifying age Execute when value set Method , When defining set When the method is used ,value、writable、configurable Not definable 
		set: function(value) {
    
			console.log(' Someone modified it age attribute , value =>'+value);
			number = value;// Yes age When modifying, assign a value to number
		}
	});
	console.log(Object.keys(person));
	// 0: "name"
	// 1: "sex"
	// length: 2
	for (let key in person) console.log(person[key]);
	//  Zhang San 
	//  male 


	//2
	// The following age Attributes can be enumerated 
	person = {
    
		name: ' Zhang San ',
		sex: ' male ',
		age: 18
	};
	console.log(Object.keys(person));
	// 0: "name"
	// 1: "sex"
	// 2: "age"
	for (let key in person) console.log(person[key]);
	//  Zhang San 
	//  male 
	// 18
</script>
原网站

版权声明
本文为[Shura MIUI]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/02/202202150128089947.html

边栏推荐

猜你喜欢

随机推荐