- A function in C++ is a block of code that performs a specific task.
Key Benefits:
- It helps in breaking a large program into smaller, manageable parts, improves code reusability, and makes programs easy to understand and maintain.
return_type function_name(parameter_list)
{
// function body
// statements
return value; // optional (if return_type is void)
}
Key points
return_type: Data type of the value returned by the function (e.g.,
int,float,void)-
function_name: Name of the function (should be meaningful)
-
parameter_list: Input values passed to the function (optional)
-
function body: Contains the logic of the function
-
return statement: Sends the result back to the calling function
Categories of Functions - Examples:
Example 1: Function without Parameters and without Return Value
#include <iostream>
using namespace std;
void greet()
{
cout << "Welcome to C++ Programming";
}
int main()
{
greet();
return 0;
}
Key Points: The function greet() simply prints a message. It does not take inputs or return any value.
Example 2: Function with Parameters and without Return Value
#include <iostream>
using namespace std;
void add(int a, int b)
{
cout << "Sum = " << a + b;
}
int main()
{
add(10, 20);
return 0;
}
Key points: The function add() receives two integers and displays their sum.
Example 3: Function with Parameters and Return Value
#include <iostream>
using namespace std;
int square(int n)
{
return n * n;
}
int main()
{
int result = square(5);
cout << "Square = " << result;
return 0;
}
Key points: The function square() calculates and returns the square of a number.
Example 4: Function without Parameters but with Return Value
using namespace std;
int square(int n)
{
return n * n;
}
int main()
{
int result = square(5);
cout << "Square = " << result;
return 0;
}
Key points: The function square() calculates and returns the square of a number.
Example 4: Function without Parameters but with Return Value
#include <iostream>
using namespace std;
int getNumber()
{
return 100;
}
int main()
{
cout << "Number = " << getNumber();
return 0;
}
Key points: The function getNumber() returns a fixed integer value.
using namespace std;
int getNumber()
{
return 100;
}
int main()
{
cout << "Number = " << getNumber();
return 0;
}
Key points: The function getNumber() returns a fixed integer value.
