I want to create a map of 48 default key value pairs. This code works fine:

var m = new Map();

for(var i=1; i <= 48 ; i++) {
  m.set(i,'0')
}

But, I want to know if this can be done without using for loop.

I want to create a map of 48 default key value pairs. This code works fine:

var m = new Map();

for(var i=1; i <= 48 ; i++) {
  m.set(i,'0')
}

But, I want to know if this can be done without using for loop.

• javascript
• ecmascript-6

• What's wrong with a for loop? – Jeremy Thille Commented Aug 29, 2017 at 17:28
• nothing just wanted to know whether this can be done without for loop or not. – prisoner_of_azkaban Commented Aug 29, 2017 at 17:29
• Using a for loop is the best way to achieve what you need – koolkat Commented Aug 29, 2017 at 17:30
• As far as I know almost all solutions will use some kind of inner loop. – Manos Kounelakis Commented Aug 29, 2017 at 20:08

1 Answer 1

You can pass an array to the Map constructor:

const map = new Map([...Array(48)].map((_, i) => [i + 1, '0']));

If your first key can be 0 instead of 1, this would be a cleaner solution:

const map = new Map(Array(48).fill('0').entries());