JS數組的交集、並集、差集，數組去重，獲取兩個數組重復的元素，去除兩個數組相同的元素

        let arr1=[1,2,3,4,5,6]
        let arr2=[4,5,6,7,8,9]
        // 並集 數組去重 
        let RemoveSame=[...new Set([...arr1,...arr2])]
        console.log(RemoveSame) //[1, 2, 3, 4, 5, 6, 7, 8, 9]

        //數組交集，或得兩個數組重復的元素
        let SamePart=arr1.filter(item=>arr2.includes(item))
        console.log(SamePart) //[4, 5, 6]

        //差集=並集-交集  去除兩個數組相同的元素
        let Difference=RemoveSame.filter(item=>!SamePart.includes(item))
        console.log(Difference) //[1, 2, 3, 7, 8, 9]