freeCodeCamp/curriculum/challenges/arabic/08-coding-interview-prep/data-structures/reverse-a-doubly-linked-list.arabic.md

id	title	challengeType	videoUrl	localeTitle
587d825a367417b2b2512c88	Reverse a Doubly Linked List	1

Description

undefined

Instructions

undefined

Tests

tests:
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; return (typeof test == "object")})(), "The DoublyLinkedList data structure exists.");'
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; if (test.add == undefined) { return false; }; return (typeof test.add == "function")})(), "The DoublyLinkedList has a method called add.");'
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; if (test.reverse == undefined) { return false; }; return (typeof test.reverse == "function")})(), "The DoublyLinkedList has a method called reverse.");'
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; return (test.reverse() == null); })(), "Reversing an empty list returns null.");'
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; test.add(58); test.add(61); test.add(32); test.reverse(); return (test.print().join("") == "326158"); })(), "The reverse method reverses the list.");'
  - text: ''
    testString: 'assert((function() { var test = false; if (typeof DoublyLinkedList !== "undefined") { test = new DoublyLinkedList() }; test.add(11); test.add(22); test.add(33); test.reverse(); return (test.printReverse().join("") == "112233"); })(), "The next and previous references are correctly maintained when a list is reversed.");'

Challenge Seed

var Node = function(data, prev) {
  this.data = data;
  this.prev = prev;
  this.next = null;
};
var DoublyLinkedList = function() {
  this.head = null;
  this.tail = null;
  // change code below this line
  // change code above this line
};

After Test

console.info('after the test');

Solution

// solution required