Run results for: multiple map iterations

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:97.0) Gecko/20100101 Firefox/97.0

Browser: Firefox 97

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
shared variables	497532.8 Ops/sec
non-shared variables	503306.1 Ops/sec
destructured	346582.3 Ops/sec

Script Preparation code:

var Map1 = new Map([
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}],
  [{}, {}]
]);

var Map2 = new Map([
  [1, 0],
  [2, 0],
  [3, 0],
  [4, 0],
  [5, 0],
  [6, 0],
  [7, 0]
]);

var Map3 = new Map([
  ['a', 'String'],
  ['b', 'String'],
  ['c', 'String'],
  ['d', 'String'],
  ['e', 'String'],
  ['f', 'String'],
  ['g', 'String']
]);

var Map4 = new Map([
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()],
  [Symbol(), new Set()]
]);

var Target = new Map();

Tests:

shared variables
let tuple, key, value for (tuple of Map1) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map2) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map3) { key = tuple[0]; value = tuple[1]; Target.set(key, value); } for (tuple of Map4) { key = tuple[0]; value = tuple[1]; Target.set(key, value); }
non-shared variables
for (const tuple of Map1) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map2) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map3) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); } for (const tuple of Map4) { const key = tuple[0]; const value = tuple[1]; Target.set(key, value); }
destructured
for (const [key, value] of Map1) { Target.set(key, value); } for (const [key, value] of Map2) { Target.set(key, value); } for (const [key, value] of Map3) { Target.set(key, value); } for (const [key, value] of Map4) { Target.set(key, value); }

Run results for: multiple map iterations

shared variables

non-shared variables

destructured