Failed to create javascript array inside another array

This is actually not an array, it is a nested object of objects. So each nested object have a pair of key and value.

let's say we got strings as key and

{
  FIRST: 'First Value',
  SECOND: 'Second Value',
  THIRD: 'Third Value',
}

as value (in this particular case, the value itself is an object too), so each key and value have to be separated by a colon.

Then, each pair should look like the below example instead of provided one:

strings: {
  FIRST: 'First Value',
  SECOND: 'Second Value',
  THIRD: 'Third Value',
}

You are getting an error in this case because you used = instead of a colon (:) and it won't be recognized as an object.

So your final object should be something like this:

var Constants = {
    strings: {
        FIRST: 'First Value',
        SECOND: 'Second Value',
        THIRD: 'Third Value',
    },
    numbers: {
        FIRST: 1,
        SECOND: 2,
        THIRD: 3,
    }
};

console.log(Constants.strings.FIRST)
console.log(Constants.numbers.FIRST)