如何使用 JavaScript 合并集合（Set）
要合并集合，请使用扩展运算符 (...) 将两个或多个集合的值合并到一个数组中，并将它们传递给 Set() 构造函数，例如 new Set([...set1, ...set2])。 新集合将包含来自提供的 Set 对象的所有元素。
const set1 = new Set(['one', 'two']);
const set2 = new Set(['three']);
const set3 = new Set([...set1, ...set2]);
console.log(set3); // 👉️ {'one', 'two', 'three'}
我们使用扩展运算符 (...) 将 2 个 Set 对象中的元素合并到一个数组中。
const set1 = new Set(['one', 'two']);
console.log([...set1]); // 👉️ ['one', 'two']
最后一步是将数组传递给 Set() 构造函数，该构造函数将一个可迭代对象作为参数。
设置好值后，新 Set 如下所示。
const set3 = new Set(['one', 'two', 'three']);
可以根据需要对尽可能多的 Set 对象重复此过程。
const set1 = new Set(['one']);
const set2 = new Set(['two']);
const set3 = new Set(['three']);
const set4 = new Set([...set1, ...set2, ...set3]);
console.log(set4); // 👉️ {'one', 'two', 'three'}
forEach等方法按元素插入顺序迭代 Set 对象。 如果需要更改插入顺序，只需在使用扩展运算符时切换解包值的顺序即可。
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