Run results for: Iteration Array for-of vs Map for-of 5

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:131.0) Gecko/20100101 Firefox/131.0

Browser: Firefox 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Array for-of

4.3M/s

Map for-of

1.0M/s

View exact numbers

Test name	Executions per second
✓ Array for-of	4,340,558 Ops/sec
Map for-of	1,036,405 Ops/sec

Script Preparation code:

var obj = {
  a: 1,
  b: 2,
  c: 3,
  d: 4,
  e: 5,
  f: 6,
  g: 7,
  h: 8,
  i: 9,
  j: 10,
  k: 11,
  l: 12,
  m: 13,
  n: 14,
  o: 15,
  p: 16,
  q: 17,
  r: 18,
  s: 19,
  t: 20,
  u: 21,
  v: 22,
  w: 23,
  x: 24,
  y: 25,
  z: 26
};
var map = new Map(Object.entries(obj));

var array = [
  [1], 
  [2], 
  [3], 
  [4], 
  [5], 
  [6], 
  [7], 
  [8], 
  [9], 
  [10], 
  [11], 
  [12], 
  [13], 
  [14], 
  [15], 
  [16], 
  [17], 
  [18], 
  [19], 
  [20], 
  [21], 
  [22], 
  [23], 
  [24], 
  [25], 
  [26], 
];

Tests:

Array for-of
let total = 0; for(const item of array){ total += item[0]; }
Map for-of
let total = 0; for (const [key, value] of map) { total += value; }