Nodejs Utililty Methods Array Index

Array.prototype.indexOfMatchFunction = function(func) {
    "use strict";
    for (var i in this) {
        if (!this.hasOwnProperty(i))
            continue;
        var element = this[i];
        if (func(element))
            return parseInt(i);
    return -1;
};

Array.prototype.indexOfObject = function(key, value)
    if(this.length == 0 ) return -1;
    for( var i = 0; i < this.length; i++)
        if(this[i][key] == value)
            return i;
    return -1;
};

Array.prototype.indexOfObject = function (myArray, searchTerm, property) {
    for(var i = 0, len = myArray.length; i < len; i++) {
        if (myArray[i][property] === searchTerm) 
        return i;
    return -1;

Array.prototype.indexOfObject = function(obj) {
  for ( var i = 0, len = this.length; i < len; i++) {
    if (angular.equals(this[i], obj))
      return i;
  return -1;
};

Array.prototype.indexOfObject = function(prop, val) {
  function traverseObject(obj) {
    if(typeof(obj) === 'object') {
      for(var e in obj) {
        if(obj[prop] == val) {
          return true;
        } else {
          return traverseObject(obj[e]);
    return false;
  for(var i = 0; i < this.length; i++) {
    if(this[i] == val) {
      return i;
    } else if(traverseObject(this[i])) {
      return i;
  return -1;
};

Array.prototype.indexOfObject = function(property, value) {
    for (var i = 0, len = this.length; i < len; i++) {
        if (this[i] !== null && this[i][property] === value) return i;
    return -1;

Array.prototype.indexOfObjectId = function indexOfObjectId(element) {
    for (var i = 0, len = this.length; i < len; i++) {
        if (this[i].equals(element)) {
            return i;
    return -1;
};

Array.prototype.indexOfSelect = function(filter)
  for (var i = 0; i< this.length; i++) {
    if(filter(this[i])){
      return i;
  return -1;

Array.prototype.indexOfSmallest = function indexOfSmallest(k) {
  let lowest = 0;
  const a = this;
  for (let i = 1; i < a.length; i++) {
    if (k) {
      if (a[i][k] < a[lowest][k]) lowest = i;
    } else {
      if (a[i] < a[lowest]) lowest = i;
  return lowest;
};