var cars = ["Banana", "Orange", "Apple", "Mango"];
var x = cars.length; // length 属性返回元素的数量
var y = cars.sort(); // sort() 方法对数组进行排序
var first = cars[0]; 访问数组
数组操作
https://www.w3school.com.cn/js/js_arrays.asp
数组方法
https://www.w3school.com.cn/js/js_array_methods.asp
原文：https://www.cnblogs.com/kaibindirver/p/13200909.html