jsPerf.app is an online JavaScript performance benchmark test runner & jsperf.com mirror. It is a complete rewrite in homage to the once excellent jsperf.com now with hopefully a more modern & maintainable codebase.
jsperf.com URLs are mirrored at the same path, e.g:
https://jsperf.com/negative-modulo/2
Can be accessed at:
https://jsperf.app/negative-modulo/2
function leftpad (str, len, ch) {
str = String(str);
var i = -1;
if (!ch && ch !== 0) ch = ' ';
len = len - str.length;
while (++i < len) {
str = ch + str;
}
return str;
}
function leftpad2(str, len, ch) {
if (!ch && ch !== 0) ch = ' ';
return (''+ch).repeat(Math.max(0, len - str.length)) + str
}
Ready to run.
Test | Ops/sec | |
---|---|---|
while loop |
| ready |
repeat and slice |
| ready |
You can edit these tests or add more tests to this page by appending /edit to the URL.