Why is the array literal syntax slower than the array constructor?

Asked Oct 12 '14 at 01:42

Active Oct 12 '14 at 06:06

Viewed 161 times

In JavaScript, we know one language rule is that Prefer array and object literals over their constructor.

However, I test it in Chrome, it seems that array literal is slower than array constructor, why?

console.time('testconstructor'); 
var li = new Array(1, 2, 3); 
console.timeEnd('testconstructor');

console.time('testliteral'); 
var li = [1, 2, 3]; 
console.timeEnd('testliteral');

The results are

testconstructor: 0.18ms
testliteral: 0.28ms

edited Oct 12 '14 at 06:06

asked Oct 12 '14 at 01:42

zangw

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What browser did you test with? In Chrome and IE 11, the array literal is consistently faster when testing in jsfiddle. – Jeff Ogata Oct 12 '14 at 01:53
1

See this: http://stackoverflow.com/questions/7375120/why-is-arr-faster-than-arr-new-array – Vinicius Braz Pinto Oct 12 '14 at 01:56
1

your timing labels are reversed. Is it possible your results are as well? – Mark Reed Oct 12 '14 at 02:19
Sorry for typo, and fix it. – zangw Oct 12 '14 at 06:07

Why is the array literal syntax slower than the array constructor?

0 Answers0