Nodejs Utililty Methods String Sub String

String.prototype.sub = function(pattern, replacement, count) {
  replacement = this.gsub.prepareReplacement(replacement);
  count = count === undefined ? 1 : count;
  return this.gsub(pattern, function(match) {
    if (--count < 0) return match[0];
    return replacement(match);
  });
};

String.prototype.sub = function(pattern, replacement, count) {
  var replacer = Object.isFunction(replacement) ?
    replacement :
    function(){ return replacement };
  count = Object.isUndefined(count) ? 1 : count;
  return this.gsub(pattern, function(match) {
    if (--count < 0) return match[0];
    return replacer(match);
  });
...

String.prototype.subString = function(){
    var arr = [];
    for(var i = 0; i < this.length; i++){
        for(var j = i + 1; j < this.length + 1; j++){
            arr.push(this.slice(i, j));
    return arr;
console.log("dog".subString());

String.prototype.subString = function()   
  var subset = [];  
  for (var m = 0; m < this.length; m++)   
    for (var n = m+1; n<this.length+1; n++)   
      subset.push(this.slice(m,n));  
  return subset;  
};  
console.log("dog".subString());

var text = 'this is  test test test we in are is';
String.prototype.subStringCounter = function (searchString) {
    var position = 0,
        counter = 0;
    searchString = searchString.toLowerCase();
    while (this.indexOf(searchString, position) >= 0) {
        counter += 1;
        position = this.toLowerCase().indexOf(searchString, position) + 1;
    return counter;
};
console.log(text.subStringCounter('in'));
console.log(text.subStringCounter('we'));

String.prototype.subStrings = function () {
  var substrings = [];
  for (var i = 0; i < this.length ; i++) {
    for (var j = i+1; j <= this.length; j++) {
      substrings.push(this.slice(i,j));
    };
  };
  return substrings;
};
...

String.prototype.subStrings = function () {
  var subs = [];
  for (var i = 0; i < this.length; i++) {
    for (var j = i + 1; j < this.length; j++) {
      subs.push(this.slice(i, (j + 1)));
  return subs;
};
...

String.prototype.subStrings = function () {
  var subs = [];
  for (var i = 0; i < this.length; i++) {
    for (var j = i+1; j <= this.length; j++) {
      subs.push(this.slice(i,j));
    };
  };
  var sorted = subs.sort();
  var uniques = [sorted[0]];
...

String.prototype.subStrings = function () {
  result = [];
  for (var beginning = 0; beginning < this.length; beginning++) {
    for (var end = beginning + 1; end < this.length + 1; end++) {
      result.push(this.slice(beginning, end));
  return result
var a = "cat";
var b = a.subStrings();
console.log(b);

String.prototype.subStrings = function(){
  const substringArray = [];
  for (var i = 0; i < this.length; i++){
    for (var j = i; j < this.length; j++){
      let substring = this.slice(i,j+1);
      if (!substringArray.includes(substring)){
        substringArray.push(substring);
  return substringArray;
console.log("abc".subStrings());