Nodejs Array Find find(criteria)

Method Source Code

Array.prototype.find = function(criteria) {
  for (var i = 0; i < this.length; i++) {
    if (criteria(this[i])) {
      return this[i]
    }// w w  w  .  j a v a 2  s . c  o m
  }
  return null
}

Math.sign = function(x) {
  if (x > 0) {
    return 1
  } else if (x < 0) {
    return -1
  } else {
    return 0
  }
}

Related

1. find()

   Array.prototype.find = function()
     var result;
       this.each(function(value, index)
       if(iterator.call(context, value, index, this))
         result = value;
         return false;
   ...
   

2. find(callback)

   Array.prototype.find = function(callback) {
      for (var i = 0; i < this.length; i++) {
         if (callback(this[i])) return this[i];
      return undefined;
   

3. find(callback)

   'use strict';
   Array.prototype.find = Array.prototype.find || function(callback) {
     if (this === null) {
       throw new TypeError('Array.prototype.find called on null or undefined');
     } else if (typeof callback !== 'function') {
       throw new TypeError('callback must be a function');
     var list = Object(this);
     var length = list.length >>> 0;
   ...
   

4. find(cond)

   Array.prototype.find = function(cond) {
     for(var i = 0, n = this.length; i < n; ++i) {
       if(cond(this[i])) {
         return this[i];
     return null;
   };
   

5. find(criteria)

   Array.prototype.find = function(criteria) {
     for (var i = 0; i < this.length; i++) {
       if (criteria(this[i])) {
         return this[i]
     return null
   

6. find(element)

   Array.prototype.find = function (element) {
     if (typeof element === 'function') {
       return element(this);
     var len = this.length;
     for (var i = 0; i < len; i++) {
       if(this[i] === element) {
         return element;
     return -1;
   var doPow = function (array) {
     var len = array.length;
     for(var i = 0; i < len; i++) {
       array[i] *= array[i]; 
     return array;
   var b = [1, 2, 3, 4, 5, 6];
   console.log(b.find(doPow));
   

7. find(element)

   Array.prototype.find = function(element) {
       var i;
       for (i = 0; i < this.length; i += 1) {
           if (this[i] === element) {
               return i;
       return false;
   

8. find(element)

   Array.prototype.find=function(element){
       var i;
       for(i=0;i<this.length;i+=1){
           if(this[i]===element){
               return i;
       return false;
   Array.prototype.remove=function(element){
       var i;
       for(i=0;i<this.length;i+=1){
           if(this[i]===element){
               this.splice(i,1)
               return true;
       return false;
   var arr=['a','b','c','d','e','f','g','h'];
   arr.remove('e');
   arr.remove('f');
   var i;
   for(i=0;i<arr.length;i+=1){
       console.log(arr[i]);
   

9. find(f)

   Array.prototype.find = function(f) {
     for (var i = 0; i < this.length; i++) {
       if (f(this[i]))
         return this[i];
   };