1.使用ES6 新增的扩展运算符和Set新数据类型判断两个数组是否包含有相同的元素

    var arr1 = ['green' , 'yellow' ,'blue' ,'red'];
    var arr2 = ['lightlue' , 'red' , 'pink'];
    var arr3 = ['yellow' ,'blue' ,'red', 'green'];

    arr1.push(...arr2);
    var arrset1 = new Set(arr1);
    if([...arrset1].length == arr2.length){
        alert("arr1和arr2两个数组相等");
    }else{
        alert('arr1 和arr2 两个数组不相等');
    }