Question

js从数组中随机获取一个元素，，已经获取过的下次不再获取

这个怎么做

Answer 1

var arr = [1,2,3];
var index = Math.floor(Math.random() * arr.length);
var tmp = {};
if(!tmp[index])
{
console.log(arr[index]);

tmp[index] = index;

}