Run results for: defineproperty vs direct assignment

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.5

Device Platform: Mobile

Date tested: one year ago

3.1M/s

9K/s

View exact numbers

Test name	Executions per second
✓ b	3,097,257 Ops/sec
a	8,772 Ops/sec

Tests:

a
var target = {}; var key = 'something'; for (var i=0; i<1000; i++) { Object.defineProperty(target, key+i, { get: function() {return _val;}, set: function(v) { target._v = v}, }); }
b
var target = {}; var key = 'something'; for (var i=0; i<1000; i++) { target[key+1] = undefined; }