Set.prototype.add() - JavaScript 编辑

add() 方法用来向一个 Set 对象的末尾添加一个指定的值。

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语法

mySet.add(value);

参数

value

必需。需要添加到 Set对象的元素的值。

返回值

Set 对象本身

注意：不能添加重复的值

示例

var mySet = new Set();

mySet.add(1);
mySet.add(5).add("some text"); // 可以链式调用

console.log(mySet);
// Set [1, 5, "some text"]

mySet.add(5).add(1);
console.log(mySet);
// Set [1, 5, "some text"]  // 重复的值没有被添加进去

规范

规范
ECMAScript (ECMA-262) Set.prototype.add

浏览器兼容性

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参见

• Set
• Set.prototype.delete()
• Set.prototype.has()