javascript - 如何在数组中使用数组变量？

Question

我有一个数组，我想将相同的数组和其他数组放入第一个数组中。

var arr=["a","b","c",arr,arr2];
var arr2=["a","b"];

var arr3=[];
arr3=arr[3]; 

当我打印出arr时，我可以看到 ["a","b","c",,]

但是如果我打印出arr3，结果是未定义的。

我该如何解决？

Answer 1

您需要按正确的顺序执行此操作:

var arr1 = [];
var arr2 = [ "a", "b" ];


// Now arr1 and arr2 are defined so you can throw them into another array:

var arr3 = [ "a", "b", "c", arr1, arr2 ];