Nodejs Utililty Methods String Contains

String.prototype.Contains = function( str )
    return this.indexOf( str ) > -1;
};

String.prototype.Contains = function( textToCheck )
  return ( this.indexOf( textToCheck ) > -1 ) ;

String.prototype.containIgnoreCase = function (otherStr) {
    return this.toLowerCase().indexOf(otherStr.toLowerCase());

String.prototype.contains  = function( s, index) {
  return this.indexOf(s,index||0) > -1;

String.prototype.contains = function() {
  var args = arguments;
  for (var i in args) {
    var str = args[i];
    if (typeof str === "string" && this.indexOf(str) > -1) {
      return true;
  return false;
...

var fs = require('fs');
var path = process.argv[2];
var suffix = '.'+process.argv[3];
var list =[];
String.prototype.contains = function() {
    return String.prototype.indexOf.apply( this, arguments ) !== -1;
};
fs.readdir(path, function(err, files){
  if(!err){
...

String.prototype.contains = function () {
  return String.prototype.indexOf.apply(this, arguments) !== -1;
};

String.prototype.contains = function (a) {
  if (this.indexOf(a) > -1)
    return true;
  else
    return false;
};

var string = "Hello world, my name is cole hudson. This is super cool.";
String.prototype.contains = function(argument){
  var parent = this.toLowerCase();
  var argumentString = argument.toLowerCase();
  return (parent.indexOf(argumentString) > -1);
};
console.log(string.contains("World"));

String.prototype.contains = function(char) {
    return this.indexOf(char) != -1;
};