ES6数组操作（并、差、交、去重）等操作

 <script>
        let arr = [1, 2, 3, 4, 5, 5, 4, 3, 2, 1];
 
        // 1. 数组去重
        let result = [...new Set(arr)];
        console.log("result: ", result);
 
        // 2. 交集
        let arr02 = [4, 5, 6, 4, 5];
        let result02 = [...new Set(arr)].filter(item => {
                let s02 = new Set(arr02);
                if (s02.has(item)) {
                    return true;
                } else {
                    return false;
                }
            })
            // true表示存在交集
        let result02Plus = [...new Set(arr)].filter(item => new Set(arr02).has(item));
        console.log("交集: ", result02Plus);
 
        // 3. 并集
        let union = [...arr, ...arr02];
        console.log(union);
 
        // 4. 差集
        let diff = [...new Set(arr)].filter(item => !(new Set(arr02).has(item)))
        console.log(diff);
    </script>