Object.seal()
JavaScript Object.seal()方法
JavaScript的
Object.seal()方法会密封对象，从而阻止向其添加新属性并将所有现有属性标记为不可配置。要密封的对象作为参数传递，该方法返回已密封的对象。
语法：
参数：
obj ：应密封的对象。
返回值：
Object.sealed()方法返回已密封的对象。
浏览器支持：
| Chrome |
6 |
| Edge |
是 |
| Firefox |
4 |
| Opera |
12 |
示例1
const obj1 = { property1: 'Marry'};
const obj2 = Object.seal(obj1);
// prevents other code from deleting properties of an object.
obj2.property1 = 'carry';
console.log(obj2.property1);
输出：
示例2
const object1 = {
property1: 29
};
Object.seal(object1);
// Prevents other code from deleting properties of an object.
object1.property1 =45;
console.log(object1.property1);
delete object1.property1;
// cannot delete when sealed
输出：
示例3
const object1 = {
property1: 42
};
Object.seal(object1);
object1.property1 = 45;
console.log(object1.property1);
delete object1.property1; // cannot delete when sealed
console.log(object1.property1);
const object2 = {
property2: 45};
object2.property2 =67;
console.log(object2.property2);
输出：
