JavaScript（js）中两个简单Array数组求交集、并集、差集和补集

我会带着你远行 2021-07-25 17:14 690阅读 0赞

**目录**

一、交集

二、并集

三、差集

四、补集

--------------------

目前使用for，for in ,for of ,for each 等循环，搭配Array.indexOf()、Array.includes()等函数都可以实现该功能，但是代码较为繁杂，不够简洁，因此，推荐使用以下方式来实现：

**注意：new Set()有去重的效果**

# 一、交集 #

方式1：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
        
        let result = arrA.filter(item => arrB.includes(item));
        console.log("result:", result);

![20210502013410726.png][]

方式2：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = arrA.filter(item => new Set(arrB).has(item));
        console.log("result:", result);

# 二、并集 #

方式1：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = [...arrA, ...arrB.filter(item => !arrA.includes(item))];
        console.log("result:", result);

![20210502013607905.png][]

方式2：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = Array.from(new Set([...arrA, ...arrB]));
        console.log("result:", result);

# 三、差集 #

比如arrA有，而arrB没有

方式1：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = arrA.filter(item => !arrB.includes(item));
        console.log("result:", result);

![20210502013721185.png][]

方式2：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = arrA.filter(item => !new Set(arrB).has(item));
        console.log("result:", result);

# 四、补集 #

两个数组各自没有的集合

方式1：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = [
          ...arrA.filter(item => !arrB.includes(item)),
          ...arrB.filter(item => !arrA.includes(item))
        ];
        console.log("result:", result);

![20210502013910180.png][]

方式2：

let arrA = ["a", "b", "c", "d"];
        let arrB = ["a", "b", "e"];
    
        let result = [
          ...arrA.filter(item => !new Set(arrB).has(item)),
          ...arrB.filter(item => !new Set(arrA).has(item))
        ];
        console.log("result:", result);

[20210502013410726.png]: /images/20210725/91a82a2877c4454cb216dc67a721527f.png
[20210502013607905.png]: /images/20210725/14d1f9661bbd44288f13a4b66fb90f5c.png
[20210502013721185.png]: /images/20210725/9e27716ff4a84bc0b3ae608694550671.png
[20210502013910180.png]: /images/20210725/692dde94304049f8a4788c8f29c5f3b3.png