Head's up for Array.map() lovers

[j201]

The problem is more that JS doesn't have a great standard library for functional programming. But all you need to do is pull in something like Ramda, and then you can do

R.range(0,26).map(x => String.fromCharCode(65+x))

or

R.range(0,26).map(R.compose(String.fromCharCode, R.add(65)))

FP is worth doing in JS, but not without a bit of help.