补全代码,从数组头部插入一个新元素"奔驰",返回新的数组长度。 var mycars = ["saab", "volvo", "bmw"]; var newlen =__1__document.write(newlen); document.write('<br/>'); document.write(mycars);

var mycars = ["saab", "volvo", "bmw"]; mycars.unshift("奔驰"); var newlen = mycars.length; document.write(newlen); document.write('<br/>'); document.write(mycars); [2024-05-20 22:22:35 | AI写代码神器 | 61点数解答]