Javascript - Loop through sparse array and replace sparse values

Question

I\'m trying to loop through a sparse array and fill in sparse elements with a value.

[\'foo\', \'bar\', , , ,].map(el => el || \'default\') // returns

Answer 1

This should do it:

function Fill(n, _default) {
  return Array.apply(null,n).map(function(val) {
    return val || _default;
  });
}
var newa = Fill(myarray, "default");
console.log(JSON.stringify(newa));

Shown working here: https://jsfiddle.net/6vqsztxg/