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Run results for: is variable undefined? typeof variable === "undefined" vs variable === undefined

Comparing whether checking is (typeof variable === "undefined") is faster than (variable === undefined)

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Run details:
Mozilla/5.0 (iPad; CPU OS 15_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/112.0.5615.167 Mobile/15E148 Safari/604.1
Chrome Mobile iOS 112
iOS 15.6
Tablet
one year ago
Test name Executions per second
typeof string is undefined 398535776.0 Ops/sec
typeof undefined is undefined 8137124.0 Ops/sec
string is undefined 8028890.0 Ops/sec
undefined is undefined 4079569.0 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