Operators in C++

An operator is a symbol or keyword that tells C++ to perform a specific operation.

int sum = 10 + 20;

Here, + is the addition operator.

An operand is a value or expression on which an operator works.

int result = 10 + 20;

Here, 10 and 20 are operands, while + is the operator.

Arithmetic operators are used to perform mathematical operations.

The + operator adds two values.

int a = 10;
int b = 20;

int result = a + b;

std::cout << result;

The result is 30.

The - operator subtracts one value from another.

int a = 30;
int b = 10;

int result = a - b;

The result is 20.

The * operator multiplies two values.

int price = 100;
int quantity = 5;

int total = price * quantity;

The value of total is 500.

The / operator performs division.

int a = 20;
int b = 5;

int result = a / b;

The result is 4.

The % operator gives the remainder of integer division.

int result = 17 % 5;

The result is 2.

Relational operators compare two values. The result is a Boolean value.

The == operator checks whether two values are equal.

int a = 10;
int b = 10;

bool result = (a == b);

Here, result is true.

The != operator checks whether two values are different.

int a = 10;
int b = 20;

bool result = (a != b);

The result is true.

The > operator checks whether the left value is greater than the right value.

int age = 25;

bool result = (age > 18);

The result is true.

The < operator checks whether the left value is less than the right value.

int age = 15;

bool result = (age < 18);

The result is true.

The >= operator checks whether a value is greater than or equal to another value.

int marks = 40;

bool passed = (marks >= 40);

The result is true.

The <= operator checks whether a value is less than or equal to another value.

int age = 18;

bool result = (age <= 18);

The result is true.

Logical operators are used to combine or modify Boolean expressions.

The && operator returns true when both conditions are true.

int age = 25;
bool hasID = true;

bool allowed = (age >= 18 && hasID);

Both conditions must be true for allowed to be true.

The || operator returns true when at least one condition is true.

bool isStudent = true;
bool isTeacher = false;

bool allowed = isStudent || isTeacher;

The result is true because one condition is true.

The ! operator reverses a Boolean value.

bool passed = true;

bool result = !passed;

The value of result becomes false.

The = operator assigns a value to a variable.

int age = 20;

age = 25;

After the second statement, age contains 25.

Compound assignment operators combine an operation with assignment.

The increment operator ++ increases a value by one. The decrement operator -- decreases a value by one.

int count = 5;

count++;
count--;

The conditional operator ?: provides a compact way to choose between two expressions based on a condition.

int age = 20;

std::string result =
    (age >= 18) ? "Adult" : "Minor";

If the condition is true, the first expression is selected; otherwise, the second expression is selected.

Bitwise operators work with the individual bits of integral values.

A unary operator works with one operand.

int a = 10;

a++;

The ++ operator works with one operand.

A binary operator works with two operands.

int result = 10 + 20;

The + operator works with two operands here.

#include <iostream>

int main() {

    int price = 100;
    int quantity = 5;

    int total = price * quantity;

    if (total >= 500) {
        std::cout << "Large order";
    } else {
        std::cout << "Normal order";
    }

    return 0;
}

This example uses arithmetic, relational, assignment, and conditional control logic together.

#include <iostream>

int main() {

    int a = 20;
    int b = 6;

    std::cout << "Addition: " << a + b << std::endl;
    std::cout << "Subtraction: " << a - b << std::endl;
    std::cout << "Multiplication: " << a * b << std::endl;
    std::cout << "Division: " << a / b << std::endl;
    std::cout << "Remainder: " << a % b << std::endl;

    std::cout << "a == b: " << (a == b) << std::endl;
    std::cout << "a > b: " << (a > b) << std::endl;

    return 0;
}

• Using = when comparison with == is intended.
• Forgetting that integer division discards the fractional part.
• Using % with floating-point operands.
• Forgetting operator precedence in complex expressions.
• Using bitwise operators when logical operators are intended.
• Changing a variable unexpectedly with increment or decrement operators.

Operators are essential for performing calculations, comparisons, assignments, logical operations, and other tasks in C++.