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Object.seal()函数详解

JavaScript的 Object.seal()方法可密封对象，以防止向其添加新属性，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，并且该方法返回已密封的对象。

Object.seal - 语法

Object.seal(obj)

Object.seal - 参数

obj :应该密封的对象。

Object.seal - 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

Example 1

复制代码

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:

"carry"

例子2

复制代码

 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:

例子3

复制代码

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);