Run results for: Count char occurrence in string

Test name	Executions per second
✓ split	4,783,513 Ops/sec
indexOf2	2,172,412 Ops/sec
indexOf1	2,021,109 Ops/sec
singleChar	578,084 Ops/sec
regex	313,846 Ops/sec

Script Preparation code:

function regex (s, c) {
  return (s.match(new RegExp(c, "g")) || []).length;
}

function split (s, c) {
  return s.split(c).length - 1;
}

function indexOf1 (s, c) {
  var i = 0, count = 0;
  while ((i = s.indexOf(c, i)) >= 0) {
    count++;
    i++;
  }
  return count;
}

function indexOf2 (s, c) {
  for (let i = -2, count = -1; i != -1; count++, i = s.indexOf(c, i + 1));
}

function singleChar (s, c) {
  for(let i = 0, count = 0, l = s.length; i < l; count += +(c === s[i++]));
}

var s = "Maecenas sed lacus erat. Sed fringilla dui ac mollis condimentum. Suspendisse bibendum nulla eros, ut lobortis orci posuere quis. Nunc fringilla ut metus ultrices dictum. Nunc elementum feugiat leo. Ut fermentum, enim vel vehicula posuere, metus eros imperdiet risus, at elementum mauris urna et quam. Ut vehicula, velit at placerat ornare, nulla nisi finibus sapien, non elementum tellus purus in ex. Donec pharetra elit in rhoncus placerat. Sed volutpat eget justo ut dapibus. Mauris consectetur turpis ac euismod aliquam. Sed pellentesque pretium nunc, nec rhoncus leo euismod ut. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur gravida sed urna quis tempus. Nam aliquet tortor convallis libero mollis luctus.";
var c = "a";

Run results for: Count char occurrence in string

http://stackoverflow.com/questions/4009756/how-to-count-string-occurrence-in-string http://stackoverflow.com/questions/881085/count-the-number-of-occurences-of-a-character-in-a-string-in-javascript

regex

split

indexOf1

indexOf2

singleChar