Nodejs Array First Predicate first(func)

Method Source Code

Array.prototype.first = function (func) {
    var length = this.length,
        item = null;/*from ww w  . jav a  2s . c  o  m*/

    for (var i = 0; i < length; i++) {
        if (func(this[i])) {
            return this[i];
        }
    }

    return item;
}

Related

1. first(f)

   Array.prototype.first = function(f){
       var i = 0;
       while(i < this.length){
           if(f == undefined){
               return this[i];
           if(f(this[i])){
              return this[i];
           i++;
       return null;
   };
   

2. first(fn)

   Array.prototype.first = function(fn) {
       if (Object.prototype.toString.call(this) !== '[object Array]') {
           throw new TypeError("`this` must be Array, not " + typeof this);
       if (typeof fn === 'undefined') {
           return this[0];
       if (typeof fn !== 'function') {
           throw new TypeError("Optional `argument[0]` must be predicate function if defined");
   ...
   

3. first(func)

   Array.prototype.first = function(func) {
     return this.where(func)[0];
   };
   

4. first(func)

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

5. first(matching)

   Array.prototype.first = function(matching) {
       for (var i = 0; i < this.length; i++) {
     var entry = this[i];
     if (matching(entry) == true)
         return this[i];
       return null;
   

6. first(n)

   Array.prototype.first = function (n) {
       'use strict';
       return this.slice(0, n || 1);
   };
   

7. first(n)

   Array.prototype.first = function(n) {
     if (this.length === 0 || n < 0) return void 0;
     if (n === undefined) return this[0];
     if (n === 0) return [];
     return this.initial(this.length - n);
   };
   

8. first(num)

   Array.prototype.first = function (num) {
      if (num !== undefined) {
         return this.slice(0, num);
      return this[0];
   };