Unlocking the Power of Stacks in Java
What is a Stack in Java?
In Java, the Stack class is a part of the collections framework, providing a robust implementation of the stack data structure. As a subclass of Vector, Stack inherits all the methods of its parent class, making it a versatile tool for developers.
How Does a Stack Work?
A stack operates on the Last In First Out (LIFO) principle, where elements are added and removed from the top of the stack. This means that the last element added to the stack is the first one to be removed.
Creating a Stack in Java
To create a stack in Java, you need to import the java.util.Stack package. Once you’ve done that, you can create a stack by declaring a variable of type Stack and specifying its type, such as Stack<String> or Stack<Integer>.
Exploring Stack Methods
The Stack class offers five unique methods that set it apart from Vector. These methods are:
Pushing Elements onto the Stack
The push() method adds an element to the top of the stack. For example:
Stack<String> stack = new Stack<>();
stack.push("Hello");
stack.push("World");
Popping Elements from the Stack
The pop() method removes an element from the top of the stack. For example:
Stack<String> stack = new Stack<>();
stack.push("Hello");
stack.push("World");
String element = stack.pop(); // element = "World"
Peeking at the Top Element
The peek() method returns the top element of the stack without removing it. For example:
Stack<String> stack = new Stack<>();
stack.push("Hello");
stack.push("World");
String element = stack.peek(); // element = "World"
Searching for Elements
The search() method finds an element in the stack and returns its position from the top. For example:
Stack<String> stack = new Stack<>();
stack.push("Hello");
stack.push("World");
int position = stack.search("Hello"); // position = 1
Checking for Emptiness
The empty() method checks whether a stack is empty or not. For example:
Stack<String> stack = new Stack<>();
boolean isEmpty = stack.empty(); // isEmpty = true
Why Use ArrayDeque Instead of Stack?
While the Stack class provides a direct implementation of the stack data structure, it’s recommended to use the ArrayDeque class instead. ArrayDeque implements the Deque interface, offering a more efficient and flexible way to implement stacks in Java. So, why not give ArrayDeque a try?