ELITE TUTORING
C++ Functions
A function is a block of code that performs a specific task.
Suppose we need to create a program to create a circle and color it. We can
create two functions to solve this problem:
• a function to draw the circle
• a function to color the circle
Dividing a complex problem into smaller chunks makes our program easy to
understand and reusable.
There are two types of function:
1. Standard Library Functions: Predefined in C++
2. User-defined Function: Created by users
C++ User-defined Function
C++ allows the programmer to define their own function.
A user-defined function groups code to perform a specific task and that group
of code is given a name (identifier).
When the function is invoked from any part of the program, it all executes the
codes defined in the body of the function.
,ELITE TUTORING
C++ Function Declaration
The syntax to declare a function is:
returnType functionName (parameter1, parameter2,...) {
// function body
}
Here's an example of a function declaration.
// function declaration
void greet() {
cout << "Hello World";
}
Here,
• the name of the function is greet()
• the return type of the function is void
• the empty parentheses mean it doesn't have any parameters
• the function body is written inside {}
Calling a Function
In the above program, we have declared a function named greet() . To use
the greet() function, we need to call it.
Here's how we can call the above greet() function.
int main() {
// calling a function
greet();
, ELITE TUTORING
}
How Function works in C++
Example 1: Display a Text
#include <iostream>
using namespace std;
// declaring a function
void greet() {
cout << "Hello there!";
}
int main() {
// calling the function
greet();
return 0;
}
Output
C++ Functions
A function is a block of code that performs a specific task.
Suppose we need to create a program to create a circle and color it. We can
create two functions to solve this problem:
• a function to draw the circle
• a function to color the circle
Dividing a complex problem into smaller chunks makes our program easy to
understand and reusable.
There are two types of function:
1. Standard Library Functions: Predefined in C++
2. User-defined Function: Created by users
C++ User-defined Function
C++ allows the programmer to define their own function.
A user-defined function groups code to perform a specific task and that group
of code is given a name (identifier).
When the function is invoked from any part of the program, it all executes the
codes defined in the body of the function.
,ELITE TUTORING
C++ Function Declaration
The syntax to declare a function is:
returnType functionName (parameter1, parameter2,...) {
// function body
}
Here's an example of a function declaration.
// function declaration
void greet() {
cout << "Hello World";
}
Here,
• the name of the function is greet()
• the return type of the function is void
• the empty parentheses mean it doesn't have any parameters
• the function body is written inside {}
Calling a Function
In the above program, we have declared a function named greet() . To use
the greet() function, we need to call it.
Here's how we can call the above greet() function.
int main() {
// calling a function
greet();
, ELITE TUTORING
}
How Function works in C++
Example 1: Display a Text
#include <iostream>
using namespace std;
// declaring a function
void greet() {
cout << "Hello there!";
}
int main() {
// calling the function
greet();
return 0;
}
Output
