Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36
Chrome 89
Windows
Desktop
3 years ago
Test name Executions per second
typeof string is undefined 746853440.0 Ops/sec
typeof undefined is undefined 5472651.5 Ops/sec
string is undefined 5716871.0 Ops/sec
undefined is undefined 2874524.8 Ops/sec
Tests:
  • typeof string is undefined

    AخA
     
    typeof "not undefined" === "undefined"
  • typeof undefined is undefined

     
    typeof undefined === "undefined"
  • string is undefined

     
    "not undefined" === undefined
  • undefined is undefined

     
    undefined === undefined