MeasureThat.net

Run results for: for ++i < length vs .forEach(t) vs for..of vs for t = entries[++i] vs for i = 0; ++i in entries vs for ++i in object vs .reduce (entries)

Compare loop performance

Go to the benchmark
Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36
Chrome 134
Windows
Desktop
one month ago
Test name Executions per second
for i < length 252.9 Ops/sec
.forEach(t) 247.6 Ops/sec
for..of 251.3 Ops/sec
for t = array[i] 251.0 Ops/sec
for i=0; i in array 257.2 Ops/sec
for i in array, 374.1 Ops/sec
.reduce 234.5 Ops/sec
Script Preparation code:
AخA
 
var object = {};
for (let i = 1; i <= 100000; i++) object[String(i)] = i;
Tests:

  • for i < length

     
    for (let entries = Object.entries(object), i = -1, length = entries.length; ++i < length;) {
      const t = entries[i];
      window.k = t[0]
      window.v = t[1];
    }

  • .forEach(t)

     
    const entries = Object.entries(object);
    entries.forEach(([k, v]) => {
      window.k = k;
      window.v = v;
    });

  • for..of

     
    const entries = Object.entries(object);
    for (const [k, v] of entries) {
      window.k = k;
      window.v = v;
    }

  • for t = array[i]

     
    for (let entries = Object.entries(object), i = -1, t; t = entries[++i]; i) {
      window.k = t[0];
      window.v = t[1];
    }

  • for i=0; i in array

     
    for (let entries = Object.entries(object), i = -1; ++i in entries;) {
      const t = entries[i];
      window.k = t[0];
      window.v = t[1];
    }

  • for i in array,

     
    for (const k in object) {
      window.k = k;
      window.v = object[k];
    }

  • .reduce

     
    const entries = Object.entries(object)
    entries.reduce((_, [k, v]) => {
      window.k = k;
      window.v = v;
    });