C++ Program to Find Largest of Three Numbers

In this post, we will learn how to find the largest of three numbers using C++ Programming language.

This program asks the user to enter three integers, then it compares all three of them and find the largest number using the following methods:

1. Using If Statement
2. Using If. . .Else Statement
3. Using Nested If. . .Else Statement

So, without further ado, let’s begin this tutorial.

C++ Program to Find Largest of Three Numbers

// C++ Program to Find Largest of Three Numbers
#include <iostream>
using namespace std;

int main(){
    int a, b, c;
    
    // Asking for input
    cout << "Enter the first number: ";
    cin >> a;
    cout << "Enter the second number: ";
    cin >> b;
    cout << "Enter the third number: ";
    cin >> c;
    
    // Checking Largest number
    if (a > b && a > c){
        cout << a << " is the largest number.";
    }
    if (b > a && b > c){
        cout << b << " is the largest number.";
    }
    if (c > a && c > b){
        cout << c << " is the largest number.";
    }
    return 0;
}

Output

Enter the first number: 42
Enter the second number: 15
Enter the third number: 48
48 is the largest number.

How Does This Program Work ?

    int a, b, c;

In this program, we have declared three int data type variables named a, b and c.

    // Asking for input
    cout << "Enter the first number: ";
    cin >> a;
    cout << "Enter the second number: ";
    cin >> b;
    cout << "Enter the third number: ";
    cin >> c;

Then, the user is asked to enter the value of all the three integers.

    if (a > b && a > c){
        cout << a << " is the largest number.";
    }

Now, we check whether a is greater than b and c or not. If yes, then a is the greatest number and we will print it.

    if (b > a && b > c){
        cout << b << " is the largest number.";
    }

If the above statement is false, then the program will check whether b is greater than a and c or not. If yes, then the program will print it otherwise it will move to check the next statement.

    if (c > a && c > b){
        cout << c << " is the largest number.";
    }

If c is greater than a and b, then clearly c is the greatest number and we’ll print it on the screen using the cout statement.

C++ Program to Find Largest of Three Numbers Using If. . .Else

// C++ Program to Find Largest of Three Numbers Using If. . .Else
#include <iostream>
using namespace std;

int main(){
    int p, q, r;
    
    // Asking for input
    cout << "Enter the first integer: ";
    cin >> p;
    cout << "Enter the second integer: ";
    cin >> q;
    cout << "Enter the third integer: ";
    cin >> r;
    
    // Comparing
    if ((p > q) && (p > r)){
        cout << p << " is the greatest number.";
    }
    else if ((q > r) && (q > p)){
        cout << q << " is the largest number.";
    }
    else{
        cout << r << " is the largest number.";
    }
    return 0;
}

Output

Enter the first integer: 21
Enter the second integer: 16
Enter the third integer: 28
28 is the largest number.

C++ Program to Find Largest  of Three Numbers Using Nested If. . .Else

// C++ Program to Find Largest of Three Numbers Using If. . .Else
#include <iostream>
using namespace std;

int main(){
    int x, y, z;
    
    // Asking for input
    cout << "Enter the first number: ";
    cin >> x;
    cout << "Enter the second number: ";
    cin >> y;
    cout << "Enter the third number: ";
    cin >> z;
    
    // Largest of three numbers
    if (x > y){
        if (x > z)
            cout << x << " is the greatest number.";
        else
            cout << z << " is the greatest number.";
    }
    else{
        if (y > z)
            cout << y << " is the greatest number.";
        else
            cout << z << " is the greatest number.";
    }
    return 0;
}

Output

Enter the first number: 12
Enter the second number: 20
Enter the third number: 8
20 is the greatest number.

Conclusion

I hope after going through this post, you understand how to find the largest of three numbers using C++ Programming language.

If you have any doubt regarding the program, feel free to contact us in the comment section. We will be delighted to assist you.

Also Read:

• C++ Hello World Program
• C++ Program to Find Area of Rectangle
• C++ Program to Find Prime Numbers
• C++ Program to Count Total Number of Notes
• C++ Program to Find Largest of Two Numbers