jessegilbride

Two of the most commonly used data structures in web development are stacks and queues. The history of pages visited in a web browser and the undo operation in a text editor are examples of operations made possible using stacks. The handling of events in web browsers often uses a queue data structure.

Stack

A stack is a data structure that stores elements in a LIFO (Last In First Out) order. It's like a stack of plates in your kitchen. When a plate is added, it is pushed towards the bottom of a stack. The last plate that you stack becomes the one on the top of the stack and it is the first one that you get to use.

A stack has two basic functions:

• push(): places data onto the top of a stack
• pop(): removes data from the top of the stack

jessegilbride

Stack and Queue Exercises

Palindromes

A palindrome is a word, phrase, or number that is spelled the same forward and backward. For example, “dad” is a palindrome; “A man, a plan, a canal: Panama” is a palindrome if you take out the spaces and ignore the punctuation; and 1,001 is a numeric palindrome. We can use a stack to determine whether or not a given string is a palindrome.

Write a function that takes a string of letters and returns true or false to determine whether it is palindromic. For example:

function is_palindrome(s) {
    s = s.toLowerCase().replace(/[^a-z]/g, "");
 // your code goes here