Howdy readers, today you will learn how to write a C++ program to find the largest of three numbers using functions.
The below program prompts the user to enter three numbers, then it computes the largest among them using a user-defined function.
The user-defined function uses comparison operators to find the largest number in the below program.
So, without any delay, let’s begin this tutorial.
C++ Program to Find Largest of Three Numbers Using Functions
C++ Program
// C++ Program to Find Largest of Three Numbers Using Functions #include <iostream> using namespace std; // User-defined function int largestNumber(int a, int b, int c){ int max; if (a >= b && a >= c){ max = a; } else if (b >= a && b >= c){ max = b; } else{ max = c; } return max; } int main(){ int num1, num2, num3, largest; // Taking input cout << "Enter the first number: "; cin >> num1; cout << "Enter the second number: "; cin >> num2; cout << "Enter the third number: "; cin >> num3; // Calling out function largest = largestNumber(num1, num2, num3); // Display result cout << "Largest number is: " << largest << endl; return 0; }
Output
Enter the first number: 18 Enter the second number: 30 Enter the third number: 27 Largest number is: 30

Explanation
int largestNumber(int a, int b, int c){ int max; if (a >= b && a >= c){ max = a; } else if (b >= a && b >= c){ max = b; } else{ max = c; } return max; }
In this program, we have defined a function named largestNumber
which passes three numbers as arguments and returns the greatest of them.
// Calling out function largest = largestNumber(num1, num2, num3);
Then, we call out the custom function in the main function. This gives us the desired result. We store the largest number in the largest
named variable.
cout << "Largest number is: " << largest << endl;
The largest number among the three is displayed on the screen using the cout
statement.
Conclusion
Today you learned how to write a C++ program to find the largest of three numbers using a function.
If you have any doubts regarding the tutorial, comment down your queries in the comment section.
Thanks for reading.
Happy Coding!!
Also Read:
- C++ Program to Find Largest of Two Numbers
- C++ Program to Find Largest of Three Numbers
- C++ Program to Find the Volume of a Cylinder
- C++ Program to Find Factorial of a Number
- C++ Program to Multiply Two Numbers Using Function