如何有条件地填充数组？

Question

I have the following JS code:

let a = false
let b = true
let c = [...(a ? {d: 1} : {})]

I'm trying to set c to [{d: 1}] if a is true, and set it to [] if a is false. It's throwing the error object is not iterable (cannot read property Symbol(Symbol.iterator))

Why is it throwing this error and how can I fix it?

Answer 1

You need to wrap the expressions in arrays.

 const a = false, b = true, c = [...(a ? [{ d: 1 }] : [])], d = [...(b ? [{ d: 1 }] : [])]; console.log(c); console.log(d);