Array.prototype.repeat= function(what, L){
 while(L) this[--L]= what;
 return this;
}

var a = Array.apply(null, Array(24)).map(function() { return 0 });

// or:
var a = Array.apply(null, Array(5)).map(Boolean).map(Number);

var aray = [ 0, 0, 0, 0, 0, 0,
             0, 0, 0, 0, 0, 0,
             0, 0, 0, 0, 0, 0,
             0, 0, 0, 0, 0, 0 ];

var array = new Array(LENGTH);
array.fill(DEFAULT_VALUE);

var array = [];
for(var i=0; i<LENGTH; ++i) array.push(DEFAULT_VALUE);

Array(24).fill(0)

var a = new Array(24);
for (var i = a.length-1; i >= 0; -- i) a[i] = 0;

function replicate (n, x) {
  var xs = [];
  for (var i = 0; i < n; ++i) {
    xs.push (x);
  }
  return xs;
}

var hellos = replicate (100, "hello");

var len = 100;
var ch = '0';
alert ( new Array(len).join( ch ) );

var _ = require('lodash');
var A = _.fill(Array(24), 0);

[].fill.call({ length: 24 }, 0);

myArray = new Array(24).fill(0)

(new Array(5).toString().replace(/,/g, "0,") + "0").split(",")

// ["0", "0", "0", "0", "0"]

just do it:
//
var a = [];
//Function 'get': to get value of a[index], if a[index] undefined, return '0'
function get(i){
  if (a[i] == null){
   a[i] = 0;
  }
  return a[i];
}
//Use:
var index = 1230020;
console.log(get(index));