为什么适配器 function 更改我的 num 数组？

Question

I want to push function such that it doesn't change my num array, but it's changing it, why? nums parameter in this function is the reference to num array

 var num = [] function push(nums) { var orig = nums.map(x => x) var newNum = pushed() nums = orig return newNum } function pushed() { num.push(1) return num } console.log("new", push(num)) console.log("old", num)

Answer 1

You are making nums to reference orig but it won't make num to reference it.

changing it to num = orig will make it work.

 var num = [] function push(nums) { var orig = nums.map(x => x) var newNum = pushed() num = orig return newNum } function pushed() { num.push(1) return num } console.log("new", push(num)) console.log("old", num)