C++ Program to Find Largest Number Among Three Numbers

In this example, you'll learn to find the largest number among three numbers using if, if else and nested if else statements.

To understand this example, you should have the knowledge of following C++ programming topics:

In this program, user is asked to enter three numbers.

Then this program finds out the largest number among three numbers entered by user and displays it with proper message.

This program can be used in more than one way.


Example 1: Find Largest Number Using if Statement

#include <iostream>
using namespace std;

int main()
{    
    float n1, n2, n3;

    cout << "Enter three numbers: ";
    cin >> n1 >> n2 >> n3;

    if(n1 >= n2 && n1 >= n3)
    {
        cout << "Largest number: " << n1;
    }

    if(n2 >= n1 && n2 >= n3)
    {
        cout << "Largest number: " << n2;
    }

    if(n3 >= n1 && n3 >= n2) {
        cout << "Largest number: " << n3;
    }

    return 0;
}

Output

Enter three numbers: 2.3
8.3
-4.2
Largest number: 8.3

Example 2: Find Largest Number Using if...else Statement

#include <iostream>
using namespace std;

int main()
{
    float n1, n2, n3;

    cout << "Enter three numbers: ";
    cin >> n1 >> n2 >> n3;

    if((n1 >= n2) && (n1 >= n3))
        cout << "Largest number: " << n1;
    else if ((n2 >= n1) && (n2 >= n3))
        cout << "Largest number: " << n2;
    else
        cout << "Largest number: " << n3;
    
    return 0;
}

Output

Enter three numbers: 2.3
8.3
-4.2
Largest number: 8.3

Example 3: Find Largest Number Using Nested if...else statement

#include <iostream>
using namespace std;

int main()
{
    float n1, n2, n3;

    cout << "Enter three numbers: ";
    cin >> n1 >> n2 >> n3;

    if (n1 >= n2)
    {
        if (n1 >= n3)
            cout << "Largest number: " << n1;
        else
            cout << "Largest number: " << n3;
    }
    else
    {
        if (n2 >= n3)
            cout << "Largest number: " << n2;
        else
            cout << "Largest number: " << n3;
    }

    return 0;
}

Output

Enter three numbers: 2.3
8.3
-4.2
Largest number: 8.3