.length vs var randomized Arrays
Date tested:
4 years ago
User agent:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36
Test name
Executions per second
no var
116333.7 Ops/sec
var
112731.7 Ops/sec
const
114471.2 Ops/sec
accessing .length x 10
10727.3 Ops/sec
storing and accessing variable x 10
11282.2 Ops/sec
Benchmark definition (click to collapse):
Script Preparation code:
for (var a=[],i=0;i<100;++i) a[i]=i; // http://stackoverflow.com/questions/962802#962890 function shuffle(array) { var tmp, current, top = array.length; if(top) while(--top) { current = Math.floor(Math.random() * (top + 1)); tmp = array[current]; array[current] = array[top]; array[top] = tmp; } return array; } var p = shuffle(a);
Tests:
no var
console.log(p.length);
var
var l = p.length; console.log(l);
const
const l = p.length; console.log(l);
accessing .length x 10
console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length); console.log(p.length);
storing and accessing variable x 10
const l = p.length; console.log(l); console.log(l); console.log(l); console.log(l); console.log(l); console.log(l); console.log(l); console.log(l); console.log(l); console.log(l);
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