MeasureThat.net

Run results for: checks if object has any key - Object.keys vs for key in

Go to the benchmark
Run details:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.36
Chrome 107
Mac OS X 10.15.7
Desktop
2 years ago
Test name Executions per second
Object.keys 304434.7 Ops/sec
for key .. in 342152.0 Ops/sec
Script Preparation code:
AخA
 
const obj = {}
new Array(1000).map((item, index) => {
    obj[index] = index
})
Tests:

  • Object.keys

    ​x
     
    const obj = {}
    new Array(1000).map((item, index) => {
        obj[index] = index
    })
    ​
    return !!Object.keys(obj).length

  • for key .. in

     
    const obj = {}
    new Array(1000).map((item, index) => {
        obj[index] = index
    })
    ​
    for(let key in obj){
        return true;
    }
    return false