How to Use the Not-Equal (!=) Operator in C++?

The not-equal operator is a fundamental comparison operator in C++ represented by “!=”. It is used for making decisions in programming and is hence called a conditional operator. In this article, we will discuss how to use the Not-Equal (!=) operator in C++.

Not-Equal (!=) Operator in C++

The not-equal operator(!=) evaluates two values and returns a boolean value.

• It returns true when both values are not equal.
• It returns false if they are equal

The not equal to the operator is a binary operator so it is used with the two operands:

operand1 != operand2

It only allows for branching when both values are different and can be used to make decisions based on a given condition.

How to Use the Not-Equal (!=) Operator in C++?

The following examples show how can we use the not-equal operator in our C++ programs:

Example 1

The below example demonstrates the use of the not-equal operator in conditional statements.

C++

// C++ program to demonstrate the use of the not-equal
// operator in conditional statements.

#include <iostream>
using namespace std;

int main()
{

    // creating two integer numbers
    int num1 = 10;
    int num2 = 20;

    // Check if the two numbers are not equal
    if (num1 != num2) {
        cout << num1 << " is not equal to " << num2 << endl;
    }
    else {
        cout << num1 << " is equal to " << num2 << endl;
    }

    return 0;
}

Output

10 is not equal to 20

Explanation: In above example, we are using Not-Equal Operator (!=) that checks whether the num1 and num2 are equal or not. As 10 and 20 are not equal so the block of code inside if statement is executed and prints ” 10 is not equal to 20 “.

Example 2

The below example demonstrates the use of not-equal operator in loops.

C++

// C++ program to demonstrate the use of not-equal operator
// in loops.

#include <iostream>
using namespace std;

#include <iostream>

int main()
{
    int arr[] = { 2, 4, 6, 8, 10 }; // Sample array
    int target = 6; // Number to find
    bool found
        = false; // Flag to indicate if the number is found

    int i = 0;
    int n = sizeof(arr)
            / sizeof(
                arr[0]); // Calculate the size of the array

    // Loop through the array using the not-equal operator
    while (i != n) {
        if (arr[i] == target) {
            found = true;
            break; // Exit the loop if the number is found
        }
        i++;
    }

    if (found) {
        cout << "Number " << target
             << " is present in the array." << endl;
    }
    else {
        cout << "Number " << target << " is not present in the array." << endl;
    }

    return 0;
}

Output

The number 6 is not present in the array.

Explanation: In above example, we are checking that a target is present in array or not by using a not equal operator to loop in array until iterator i is not equal to size of array.