Run details:
Mozilla/5.0 (iPhone; CPU iPhone OS 15_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.5 Mobile/15E148 Safari/604.1
Mobile Safari 15
iOS 15.5
Mobile
one year ago
Test name Executions per second
undefined 8393813.0 Ops/sec
void 0 20734222.0 Ops/sec
constant containing undefined 12156584.0 Ops/sec
Script Preparation code:
AخA
 
var a = 1, u = void 0;
Tests:
  • undefined

     
    if(a===undefined)console.log(a);
  • void 0

     
    if(a===void 0)console.log(a);
  • constant containing undefined

     
    if(a===u)console.log(a);