Array Inject

💡 Ideas
1

Today I had to create a function which added one element after every single element in an array. E.g.
['a', 'a', 'a'] => ['a', 'b', 'a', 'b', 'a', 'b']

Because of the nice array methods like map, and filter and such I searched for a similar method for injecting elements accepting an arrow function but I couldn't find one. I thought an inject method might be a nice addition following this pattern:
[1,2,3].inject(el => el > 2, el => el += 2);

The first parameter being a boolean function to see where to inject a new element, and the second parameter being or returning a value to inject in that position giving the result:
[1,2,3,5,4,6]

Like map it wouldn't mutate the original array but instead return a new one.
I'd like to hear what other people think of this idea.

2

Hello Roy!

The more generic abstraction over map and filter would be flatMap. With that, you can easily achieve the results you're looking for:

['a', 'a', 'a'].flatMap(x => [x, 'b'])

[1,2,3,4].flatMap(el => el>2 ? [el, el+2] : [el])
3

Oh cool, I didn't know flatMap was used for this, i will rewrite my function using this method thank you!

4 
while(element = array.pop()){
      array0.push(element)
      array0.push(elementAfterEachElementInArray)
}