In this guide, we will explore the process of constructing a stack using User-Defined Data Types in C++. Prior to delving into the specifics of stack creation, it is essential to have a solid understanding of the stack data structure.
What does std::stack mean?
A data structure known as a stack operates using the Last In, First Out (LIFO) principle. Elements can only be added to and removed from one end of the std::stack.
The std::stack class serves as an adapter for containers. It enables the storage of similar data types in container objects, allowing the combination of various sequence containers to create a stack data structure. In cases where no specific container is specified, the deque container is utilized by default. Container adapters like std::stack do not support data manipulation through iterators.
In C++, a method to form a stack of custom data types involves using the std::stack container adapter in conjunction with additional functionalities provided by the Standard Template Library (STL).
Syntax:
It has the following syntax:
stack<DataType> NameOfTheStack;
- stack: The Standard Template Library (STL) in C++ provides the template class stack. It represents a stack data structure in which items are added and deleted from the same end, referred to as the top of the stack, by the Last In, First Out (LIFO) principle.
- <DataType>: The data type of the elements that will be stored in the stack is indicated by this placeholder. The actual data type we want to use has been replaced with DataType . Some examples are int, double, string, and even user-defined types (classes).
- NameOfTheStack: The stack variable is referred to by this name. Any valid identifier may be used as the name. Here, the name NameOfTheStack is used as an example.
Stack Operations:
Basic operations supported by a C++ stack include:
- Push: An item is added to or pushed into the stack.
- Pop: It allows an object on the stack to be removed or pop.
- Peek: It returns the top element in the stack without taking it down.
- isFull: Determines if a stack is filled.
- isEmpty: Determines if a stack is empty.
Example:
Let's consider an instance to demonstrate the process of forming a stack with custom data types in C++.
#include <iostream>
#include <stack>
#include <string>
// Defining a class representing a Demo.
class Demo
{
private:
std::string name;
int age;
public:
// Constructor
Demo(const std::string& n, int a) : name(n), age(a) {}
// Getter methods
std::string getName() const { return name; }
int getAge() const { return age; }
// Overload the << operator for printing
friend std::ostream& operator<<(std::ostream& os, const Demo& d)
{
os << "The name of the student is: " << d.name << ", Age of the student is: " << d.age;
return os;
}
};
int main()
{
// Creating a stack of Demo objects
std::stack<Demo> demo_Stack;
// Push some Demo objects into the stack
demo_Stack.push(Demo("Johnson", 27));
demo_Stack.push(Demo("Joseph", 29));
demo_Stack.push(Demo("Jacob", 28));
// Printing the top student in the stack
if (!demo_Stack.empty())
{
std::cout << "The top student name in the stack is: " << demo_Stack.top() << std::endl;
}
// Pop one student from the stack
if (!demo_Stack.empty())
{
demo_Stack.pop();
}
// Checking if the stack is empty after popping objects.
if (demo_Stack.empty())
{
std::cout << "Stack is empty after popping the elements." << std::endl;
}
// Push another student into the stack
demo_Stack.push(Demo("Jacob", 26));
// Printing all the students in the stack
std::cout << "Students in the stack are:" << std::endl;
while (!demo_Stack.empty())
{
std::cout << demo_Stack.top() << std::endl;
demo_Stack.pop();
}
return 0;
}
Output:
The top student name in the stack is: Name of the student is: Jacob, Age of the student is: 28
Students in the stack are:
The name of the student is: Jacob, Age of the student is: 26
The name of the student is: Joseph, Age of the student is: 29
The name of the student is: Johnson, Age of the student is: 27
Explanation:
In this illustration, the following code exhibits the handling of a collection of user-defined entities (Demo objects) in C++ by employing a stack. It showcases methods for retrieving the top element, adding elements, removing elements, verifying emptiness, and other essential stack functionalities. Additionally, it displays the process of operator overloading, like <<, for customizing output in user-defined classes.
Applications of the stack:
Management of Function Calls is one of the primary uses of the stack in C++.
Programming languages frequently rely on stacks to manage function calls and return addresses.
A function's arguments, internal variables, and memory location for resuming execution are pushed onto the stack during its invocation and popped off upon completion.
- Calculating an Expression
Arithmetic equations, such as infix, postfix, and prefix expressions, are computed with the help of stacks.
During the evaluation process, operators and operands are organized in a stack, with operations performed based on their associativity and precedence.
- Evolution of web browsers
Users can navigate through previously visited websites using stacks to handle their browsing history effectively.
- Undo/Redo Capabilities
Stacks are frequently employed in text editing software and graphic applications to implement undo and redo features, enabling users to reverse modifications made to documents or designs.
- Memory Management
In computing systems, stacks play a vital role in memory management.
Stack-oriented data structures, such as the call stack and frames, are commonly employed for managing memory allocation and release.
