前端笔试题（3）-使用Set去重合并

1.去重

arr1=[1,1,2,2,3,3,3,4]
arr2=[...new Set(arr1)]//[1,2,3,4]

2.去重加合并

(1)复杂

function union(arr1:any, arr2:any) {
   const setA = new Set(arr1)
   const setB = new Set(arr2)
    let _union = new Set(setA)
    for (let elem of setB) {
        _union.add(elem);
    }
    return [..._union];
}

union([1, 2, 3], [2, 3, 4])//[1,2,3,4]

（2）更简单的（先合并再去重）

function union(arr1:any,arr2:any) {
    const setA = new Set([...arr1, ...arr2])
    return [...setA]
}