Run results for: leftpad

Run details:

User agent: Mozilla/5.0 (Android 10; Mobile; rv:132.0) Gecko/132.0 Firefox/132.0

Browser: Firefox Mobile 132

Operating system: Android

Device Platform: Mobile

Date tested: one year ago

Benchmark engine: Benchmark.js

mine

2.3M/s

fastleftpad

2.0M/s

leftpad

593K/s

View exact numbers

Test name	Executions per second
✓ mine	2,332,544 Ops/sec
fastleftpad	2,043,461 Ops/sec
leftpad	592,859 Ops/sec

Script Preparation code:

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 fastleftPad(value, size, pad) {
  if (value.length < size) {
    size -= value.length;
    var res = '';
    for(;;) {
      if (size & 1) res += pad;
        size >>= 1;
        if (size) pad += pad;
          else break;
    }
    return res + value;
  }
  return value;
}

function myleftpad (str, len, ch) {
  len=len-str.length;
  str+=ch.repeat(len);
  return str;
}

Tests:

leftpad
leftpad('anim',20,'0')
fastleftpad
fastleftPad('anim',20,'0')
mine
myleftpad('anim',20,'0')

blah

leftpad

fastleftpad

mine