JSFiddle - React, Tailwind, and code Playground

JavaScript

function fillArrayWithNumber(n) {
        var arr = Array.apply(null, Array(n));
        return arr.map(function (x, i) { return 0 });
    }

function fillArrayWithIndex(n) {
        var arr = Array.apply(null, Array(n));
        return arr.map(function (x, i) { return i });
    }

console.log(fillArrayWithNumber(5));
console.log(fillArrayWithIndex(5));