javascript 集合 交集 并集 差集

    let arr1 = [1,2,7,4,9,5,3,2]
    let arr2 = [2,3,5,6]

    //去重利用集合，并返回数组
    let uniq = [...new Set(arr1)]
    console.log(uniq); 
    
    //求交集
    let jiaoji = arr2.filter(item=>uniq.includes(item))
    console.log(jiaoji)

    //求并集
    let bingji = new Set([...arr1 , ...arr2]);
    console.log(bingji)

    //求差集
    let chaji = arr2.filter(item=>!(uniq.includes(item)) )
    console.log(chaji)