宣布一个数组的长度

Question

var names=new Array("Charlie","Auggie","Hunter","Diesel","Harlum","Tank","Runt");
    var rnames=Math.floor(Math.random(1,names.length));

那是我的代码,rnames总是0.我怎么告诉表的长度？(长度为7 - 换句话说,我想告诉表中有多少条目.)

Answer 1

在Javascript中,Math.random()不带任何参数.
您传递的任何参数都会被忽略,并且它始终返回0到1之间的实数.

相反,您应该将数字乘以数组的长度,如下所示:

var names = ["Charlie","Auggie","Hunter","Diesel","Harlum","Tank","Runt"];
var randomIndex = Math.floor(Math.random() * names.length);