Chapter 4: Operators in C++

Operators are special symbols that perform operations on variables and values. They are used to calculate results, compare values, assign data, and perform logical or bitwise operations.

For example:

cppCopy
1int a = 10;
2int b = 5;
3
4cout << a + b;

Output

textCopy
115

In the example above, the + operator adds two numbers.

Types of Operators in C++

C++ provides several categories of operators:

• Arithmetic Operators
• Assignment Operators
• Comparison (Relational) Operators
• Logical Operators
• Bitwise Operators

1. Arithmetic Operators

Arithmetic operators perform mathematical calculations.

Example

cppCopy
1#include <iostream>
2
3using namespace std;
4
5int main()
6{
7    int a = 10;
8    int b = 3;
9
10    cout << "Addition: " << a + b << endl;
11    cout << "Subtraction: " << a - b << endl;
12    cout << "Multiplication: " << a * b << endl;
13    cout << "Division: " << a / b << endl;
14    cout << "Remainder: " << a % b << endl;
15
16    return 0;
17}

Output

textCopy
1Addition: 13
2Subtraction: 7
3Multiplication: 30
4Division: 3
5Remainder: 1

2. Assignment Operators

Assignment operators assign or update values stored in variables.

Example

cppCopy
1int x = 10;
2
3x += 5;
4
5cout << x;

Output

textCopy
115

3. Comparison (Relational) Operators

Comparison operators compare two values and return true or false.

Example

cppCopy
1int a = 10;
2int b = 20;
3
4cout << (a < b);

Output

textCopy
11

1 represents true, while 0 represents false.

4. Logical Operators

Logical operators combine or reverse Boolean expressions.

Example

cppCopy
1int age = 22;
2
3cout << (age >= 18 && age <= 60);

Output

textCopy
11

5. Bitwise Operators

Bitwise operators work directly with the binary representation of integers.

Example

cppCopy
1int a = 5;
2int b = 3;
3
4cout << (a & b);

Output

textCopy
11

Operator Precedence

When multiple operators appear in an expression, C++ follows operator precedence.

Example:

cppCopy
1int result = 5 + 3 * 2;

Output

textCopy
111

Multiplication is performed before addition.

Use parentheses to control evaluation order.

cppCopy
1int result = (5 + 3) * 2;

Output

textCopy
116

Best Practices

• Use parentheses to improve readability.
• Choose meaningful variable names.
• Avoid overly complex expressions.
• Be careful with integer division.
• Use logical operators for conditions.
• Use bitwise operators only when required.

Common Mistakes

Integer Division

cppCopy
1cout << 5 / 2;

Output

textCopy
12

To get a decimal result:

cppCopy
1cout << 5.0 / 2;

Output

textCopy
12.5

Using = Instead of ==

Incorrect:

cppCopy
1if (a = 10)

Correct:

cppCopy
1if (a == 10)

Practice Exercises

1. Write a program to perform all arithmetic operations on two numbers.
2. Compare two numbers using relational operators.
3. Check whether a person is eligible to vote using logical operators.
4. Demonstrate the use of assignment operators.
5. Perform left and right bitwise shift operations on an integer.

Summary

In this chapter, you learned:

• What operators are in C++.
• How arithmetic operators perform mathematical calculations.
• How assignment operators update variable values.
• How comparison operators compare values.
• How logical operators evaluate conditions.
• How bitwise operators manipulate binary data.
• The importance of operator precedence and parentheses.

In the next module, you'll learn Decision Making in C++, including if, if...else, nested if, switch, and the conditional (ternary) operator to make your programs respond to different conditions.