Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
stack empty() and stack size() in C++ STL
In this article we will be discussing the working, syntax and examples of stack::empty() and stack::size() function in C++ STL.
What is Stack in C++ STL?
Stacks are the data structure that stores the data in LIFO (Last In First Out) where we do insertion and deletion from the top of the last element inserted. Like a stack of plates, if we want to push a new plate into the stack we insert on the top and if we want to remove the plate from the stack we then also remove it from the top.
What is stack::empty()?
stack::empty() function is an inbuilt function in C++ STL, which is defined in <stack>header file. empty() is used to check whether the associated container is empty or not and return true or false accordingly.
The function checks the container should be empty means the size of the container should be 0.
Syntax
stack_name.empty();
Parameters
The function accepts no parameter(s).
Return value
This function returns true if the container is empty, else false.
Input
std::stack<int> stack1; stack1.emplace(1); stack1.emplace(2); stack1.emplace(3); stack1.empty();
Output
false
Input
std::stack<int> stack2; stack2.empty();
Output
true
Example
#include <iostream>
#include <stack>
using namespace std;
int main(){
stack<int> stck;
int Product = 1;
stck.push(1);
stck.push(2);
stck.push(3);
stck.push(4);
stck.push(5);
stck.push(6);
while (!stck.empty()){
Product = Product * stck.top();
stck.pop();
}
cout<<"\nProduct of elements in stack are: "<<Product;
return 0;
}Output
If we run the above code it will generate the following output −
Product of elements in stack are: 720
What is stack::size()?
stack::size() function is an inbuilt function in C++ STL, which is defined in <stack>header file. size() is used to check the associated container’s size and return the result in an integer value, which is the number of elements in the container.
If the container is empty the size() returns 0
Syntax
stack_name.size();
Parameters
The function accepts no parameter(s).
Return value
This function returns the size of the container
Input
std::stack<int> stack1; stack1.emplace(1); stack1.emplace(2); stack1.emplace(3); stack1.size();
Output
3
Input
std::stack<int> stack2; stack2.size();
Output
0
Example
#include <iostream>
#include <stack>
using namespace std;
int main(){
stack<int> stck;
int Product = 1;
stck.push(1);
stck.push(2);
stck.push(3);
stck.push(4);
stck.push(5);
stck.push(6);
cout<<"size of stack is: "<<stck.size();
while (stck.size()>0){
Product = Product * stck.top();
stck.pop();
}
cout<<"\nProduct of elements in stack are: "<<Product;
return 0;
}Output
If we run the above code it will generate the following output −
size of stack is: 6 Product of elements in stack are: 720
5K+ Views
