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');
}