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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 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.0
Firefox 127
Windows
Desktop
9 months ago
Test name Executions per second
typeof string is undefined 1133128832.0 Ops/sec
typeof undefined is undefined 1017315904.0 Ops/sec
string is undefined 1119731072.0 Ops/sec
undefined is undefined 1095505792.0 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