Question

I’m trying to push multiple elements as one array, but getting an error:

> a = []
[]
> a.push.apply(null, [1,2])
TypeError: Array.prototype.push called on null or undefined

I’m trying to do similar stuff that I’d do in ruby, I was thinking that apply is something like *.

>> a = []
=> []
>> a.push(*[1,2])
=> [1, 2]

Answer 1

When using most functions of objects with apply or call, the context parameter MUST be the object you are working on.

In this case, you need a.push.apply(a, [1,2]) (or more correctly Array.prototype.push.apply(a, [1,2]))