[] .concat(["x","y"],"z") - >如何获得[["x","y"],"z"]而不是["x","y", "Z"]？

Question

这很奇怪,但我找不到任何简单的解决方案.

注意:我使用不变性,所以我绝对不想修改原始数组(不建议使用push)

[].concat(["x","y"],"z")- >如何[["x","y"],"z"]取而代之["x","y","z"]？

Answer 1

您可以使用嵌套数组:

> [].concat([["x", "y"]], "z")

[["x", "y"], "z"]