How to Use Arithmetic Operators in C++: Syntax and Examples

In C++, you use +, -, *, /, and % as arithmetic operators to perform addition, subtraction, multiplication, division, and modulus operations on numbers. These operators work with variables and literals to calculate values in expressions.

Syntax

Arithmetic operators in C++ are used between two operands (numbers or variables) to perform calculations. The common operators are:

• + for addition
• - for subtraction
• * for multiplication
• / for division
• % for modulus (remainder of division, only for integers)

Example syntax: result = a + b; adds a and b and stores the result.

cpp

int a = 5;
int b = 3;
int sum = a + b; // sum is 8
int diff = a - b; // diff is 2
int prod = a * b; // prod is 15
int quot = a / b; // quot is 1 (integer division)
int rem = a % b; // rem is 2 (remainder)

Example

This example shows how to use arithmetic operators to calculate and print results of basic math operations.

cpp

#include <iostream>

int main() {
    int x = 10;
    int y = 4;

    std::cout << "x + y = " << x + y << "\n";
    std::cout << "x - y = " << x - y << "\n";
    std::cout << "x * y = " << x * y << "\n";
    std::cout << "x / y = " << x / y << "\n";
    std::cout << "x % y = " << x % y << "\n";

    return 0;
}

Output

x + y = 14
x - y = 6
x * y = 40
x / y = 2
x % y = 2

Common Pitfalls

Common mistakes when using arithmetic operators in C++ include:

• Using / with integers results in integer division, which discards the decimal part.
• Using % with non-integer types causes errors because modulus works only with integers.
• Dividing by zero causes a runtime error or crash.

Always ensure the divisor is not zero and use floating-point types for decimal division.

cpp

/* Wrong: integer division loses decimals */
int a = 7;
int b = 2;
int result = a / b; // result is 3, not 3.5

/* Right: use float or double for decimal division */
double c = 7.0;
double d = 2.0;
double result2 = c / d; // result2 is 3.5

Quick Reference

Operator	Meaning	Example	Result
+	Addition	5 + 3	8
-	Subtraction	5 - 3	2
*	Multiplication	5 * 3	15
/	Division (integer or floating)	5 / 2	2 (int), 2.5 (float)
%	Modulus (remainder)	5 % 3	2

Key Takeaways

Use +, -, *, /, and % to perform basic math operations in C++.

Integer division truncates decimals; use float or double for precise division.

Modulus operator % works only with integers to find the remainder.

Avoid dividing by zero to prevent runtime errors.

Arithmetic operators work between variables and literals in expressions.