Data Structures and Algorithms in Swift: Implement Stacks, Queues, Dictionaries, and Lists in Your Apps

© Elshad Karimov 2020

E. KarimovData Structures and Algorithms in Swifthttps://doi.org/10.1007/978-1-4842-5769-2_4

4. Stacks

Elshad Karimov¹ 

(1)

New York, New York, USA

 

A stack is a last in first out (LIFO) data structure. The structure of a stack can be imagined as a pile of objects stacked vertically (Figure 4-1). When extracting these objects, the last added to the stack is the first one removed. Stacks are similar to arrays but with limited control.

Figure 4-1

Stack structure

There are three methods that stacks implement. By using push() method, a new element can be added to the top of the stack, pop() method to remove an element from the top, and ...