Nodejs Utililty Methods String Count Char

String.prototype.countChars = function(c) {
  var cpt = 0;
  for(var i=0;i<this.length;i++) {
    if(this.charAt(i)==c) cpt++;
  return cpt;
var monTexte = "Je s uis un texte";
console.log(monTexte.countChars(' '));
...

var fs = require('fs');
String.prototype.countOf = function(char) {
  return this.split(char).length - 1;
fs.readFile(process.argv[2], 'utf8', function(err, data) {
  if (err) {
    console.error(err);
    return;
  var lines = data.countOf('\n');
  console.log(lines);
});

var fs = require('fs');
String.prototype.countOf = function(char) {
  return this.split(char).length - 1;
if (process.argv.length >= 3) {
  var buffer = fs.readFileSync(process.argv[2]);
  var str = buffer.toString();
  var count = str.countOf('\n');
  console.log(count);
...

String.prototype.countWords = function(){
  return this.split(/\s+/).length;
'olly olly in come free'.countWords();