Nodejs Array Last last(fn, scope)

Method Source Code

// Returns last element in array, or last element that matches a predicate fn

Array.prototype.last = function(fn, scope) {

    // Prototypes throw TypeErrors when the context or arguments are invalid

    if (Object.prototype.toString.call(this) !== '[object Array]') {
        throw new TypeError("`this` must be Array, not " + typeof this);
    }//w w  w  . j a  v a 2 s . com

    // No predicate? Return last element

    if (typeof fn === 'undefined') {
        return this[this.length - 1];
    }

    // Return last element that meets predicate

    if (typeof fn !== 'function') {
        throw new TypeError("Optional argument[0] must be predicate function if defined");
    }

    for (var i = this.length - 1; i >= 0; i--) {
        var element = this[i];
        if (fn.call(scope || this, element, i, this)) {
            return element;
        }
    }
};

Related

1. last()

   Array.prototype.last = function() {
     return this[this.length-1];
   

2. last()

   Array.prototype.last = function ()
     return this[ (this.length-1) ];
   };
   

3. last()

   Array.prototype.last = function() {
       if (this.isEmpty()) {
           return null;
       return this[this.length - 1];
   };
   

4. last()

   Array.prototype.last = function() {
       if (this.length == 0) return null
       return this.slice(this.length - 1)[0]
   

5. last(arr)

   Array.prototype.last = function (arr) {
     return this[this.length-1]
   

6. last(func)

   Array.prototype.last = function (func) {
       var length = this.length - 1,
           item = null;
       for (var i = length; i >= 0; i--) {
           if (func(this[i])) {
               item = this[i];
               break;
       return item;
   

7. last(n)

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

8. last(n)

   Array.prototype.last = function(n) {
     if (this.length == 0 || n < 0) return void 0;
     if (n == undefined) return this[this.length - 1];
     if (n == 0) return [];
     return this.rest(this.length - n);
   };
   

9. last(num)

   Array.prototype.last = function (num) {
      if (num !== undefined) {
         return this.slice(-num);
      return this[this.length - 1];
   };