Run results for: Map() delete while iterating vs clear

When iterating over a Map and clearing after iteration is required, is it faster to remove items at each iteration step or is it faster to iterate and then clear() the entire Map afterwards?

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36

Browser: Chrome 96

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Iterate + clear	5626575.5 Ops/sec
Iterate + delete	15872238.0 Ops/sec

Script Preparation code:

var dummy = 0;
var map = new Map(new Array(100).fill(null).map((_, i) => [
  function(incrementBy) {
  	dummy += incrementBy;
  },
  { incrementBy: i }
]));

Tests:

Iterate + clear
for (const [fn, obj] of map) { fn(obj.incrementBy); } map.clear();
Iterate + delete
for (const [fn, obj] of map) { fn(obj.incrementBy); map.delete(fn); }

Run results for: Map() delete while iterating vs clear

When iterating over a Map and clearing after iteration is required, is it faster to remove items at each iteration step or is it faster to iterate and then clear() the entire Map afterwards?

Iterate + clear

Iterate + delete