Cannot Read Property 'push' Of Undefined On An Array Of Objects

So currently I have an Object of arrays, to fill with objects. What I have currently is something like so: ... let foo = { 'a' : [], 'b' : [], 'c' : [] } then, let obj =

Solution 1:

The code you described works fine. I have included a snippet here. This type of non-answer response usually helps a user realize that there is something else wrong with their code. If knowing that this code works doesn't help you find your issue, try to provide a minimal, runnable example that duplicates your error.

let foo = {
   "a" : [],
   "b" : [],
   "c" : []
}

let obj = {
  d: 'hello world',
};

foo["a"].push(obj);

console.log( foo["a"] );