cachaito
6/30/2014 - 8:11 PM

Comparing loops timings

Pętla zliczając od końca do 0 jest nieznacznie szybsza! PS. zwróć uwagę na console.time() i console.timeEnd();

for loop test.js
content_copyfile_download
// generating simple 10000 entries
var a = [];
for(var i = 0; i<10000; i++) { a[i] = i; }

console.time('testing_forward');
for (var i = 0; i < a.length; i++);
console.timeEnd('testing_forward');
// output: testing_forward: 8.81ms

console.time('testing_backwards');
for (var i = a.length - 1; i >= 0; i--); // i-=1 = 6.64ms!!!!
console.timeEnd('testing_backwards');
// output: testing_backwards: 8.36ms

console.time('testing_backwards_adv');
var count = a.length;
for(;count--;);
console.timeEnd('testing_backwards_adv');
// output: testing_backwards_adv: 4.26ms