Nodejs Array First Item first()

Method Source Code

// A JavaScript object is a table mapping string property names to values.
// This makes objects pleasantly lightweight for implemeting dictionaries:
// variable-sized collections mapping strings to values.

var dict = { path: 24, montes:23, mike: 37, andrea: 21}
var friends = []/*from   w w  w .ja va2  s . c om*/


for (var name in dict) {
  friends.push(name + ":" + dict[name])
}

console.log(friends)

// Deceptively, since we can add propertie to any type of JavaScript object 
// this usage pattern will sometimes appear to work:

var dictAux = {}

dictAux.alice = 34
dictAux.bob = 4
dictAu.chirs = 3

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

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

var names = []

for (var name in dictAux) {
  names.push(name)
}

console.log(names)

Related

1. first()

   Array.prototype.first = function() {
     return this[0];
   Array.prototype.last = function() {
     return this.reverse()[0];
   

2. first()

   Array.prototype.first = function(){
       if(this.length > 0)
           return this[0];
       return null;
   };
   

3. first()

   Array.prototype.first = function() {
     if (this[0] !== undefined)
       return this[0]
     else {
       throw new TypeError("Can't get first element of an empty array.")
   

4. first()

   "use strict";
   Array.prototype.first = function  () {
     if (this.length === 0) {
       throw "Empty string doesn't have first element";
     return this[0];
   };
   console.log(["a", "b", 3].first());
   

5. first()

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

6. first()

   Array.prototype.first = function(){
       if (this.length > 0)
           return this[0];
       else
           return [];
   

7. first()

   Array.prototype.first = function () {
       this.current = 0;
       return jQuery.extend(true, [], this[this.current]);
   };
   Array.prototype.last = function () {
       this.current = this.length - 1;
       return jQuery.extend(true, [], this[this.length - 1]);
   };
   Array.prototype.next = function () {
   ...
   

8. first()

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

9. first()

   Array.prototype.first = function() {
     return this[0];
   Array.prototype.last = function() {
     return this[this.length-1];