Operators in C++: Arithmetic, Comparison, Logical

Learn arithmetic, comparison, and logical operators in C++ to perform calculations and control program flow effectively.

In C++, operators are special symbols that perform operations on variables or constants. They are used in many areas, from arithmetic calculations to logical comparisons. In this article, we will learn the most common operator types in C++ — arithmetic, comparison, and logical — with examples.

1. Arithmetic Operators

Arithmetic operators are used to perform mathematical operations.

Operator	Description	Example
`+`	Addition	`a + b`
`-`	Subtraction	`a - b`
`*`	Multiplication	`a * b`
`/`	Division	`a / b`
`%`	Modulo (remainder)	`a % b`

Simple example:


#include <iostream>
using namespace std;

int main() {
    int a = 10, b = 3;

    cout << "Sum: " << a + b << endl;
    cout << "Difference: " << a - b << endl;
    cout << "Product: " << a * b << endl;
    cout << "Quotient: " << a / b << endl;
    cout << "Remainder: " << a % b << endl;

    return 0;
}

Output:


Sum: 13
Difference: 7
Product: 30
Quotient: 3
Remainder: 1

2. Increment and Decrement Operators

In C++, there are special operators to increase or decrease numeric variables by 1:

Operator	Description	Example
`++`	Increment by one	`x++` or `++x`
`--`	Decrement by one	`x--` or `--x`


int x = 5;
cout << x++ << endl; // prints first, then increments → 5
cout << ++x << endl; // increments first, then prints → 7

The difference between x++ (postfix) and ++x (prefix) is especially important in loops.

3. Comparison Operators

Comparison operators compare two values and return the result as true or false.

Operator	Description	Example
`==`	Equal to?	`a == b`
`!=`	Not equal to?	`a != b`
`>`	Greater than?	`a > b`
`<`	Less than?	`a < b`
`>=`	Greater than or equal to?	`a >= b`
`<=`	Less than or equal to?	`a <= b`


int a = 10, b = 20;

cout << (a == b) << endl; // 0 → false
cout << (a != b) << endl; // 1 → true
cout << (a < b) << endl;  // 1 → true

When you print logical results with cout, false is shown as 0 and true as 1.

4. Logical Operators

Logical operators are used to combine multiple conditions.

Operator	Description	Example
`&&`	AND	`(a > 0 && b > 0)`
`\|\|`	OR	`(a > 0 \|\| b > 0)`
`!`	NOT	`!(a > 0)`


bool x = true;
bool y = false;

cout << (x && y) << endl; // 0 → false
cout << (x || y) << endl; // 1 → true
cout << (!x) << endl;    // 0 → false

In the && (AND) operator, the result is true only if both conditions are true. In the || (OR) operator, the result is true if at least one condition is true.

5. Example Application: Exam Result Evaluation

The example below demonstrates the combined use of arithmetic and logical operators.


#include <iostream>
using namespace std;

int main() {
    int midterm = 70;
    int finalExam = 80;

    double average = (midterm * 0.4) + (finalExam * 0.6);
    bool passed = (average >= 60) && (finalExam >= 50);

    cout << "Average: " << average << endl;
    cout << "Result: " << (passed ? "Passed" : "Failed") << endl;

    return 0;
}