Operators in C++

Operators in C++ are the symbols used for performing operations on the values or the variables. Operator tells the compiler to perform a mathematical or logical operation. There are different types of operators for performing different operations.

An operator operates operands. For example:

int c = a + b;

Here, ‘+’ is the addition operator, ‘a’ and ‘b’ are the operands.

Types of Operators in C++

There are six different types of operators in C++:

1. Arithmetic Operators
2. Assignment Operators
3. Relational Operators
4. Logical Operators
5. Bitwise Operators
6. Other Operators

Arithmetic Operators

Arithmetic operators are used to perform arithmetic or mathematical operations such as addition, subtraction, multiplication or division, etc.

There are two types of Arithmetic operators:

1. Unary Operators — Unary arithmetic operators only work with a single operand. There are four types of unary operators:
• Unary plus - The symbol + is used to represent the unary plus operator. It does not change the operand value.

        a =  +1
        b = a //here b = 1
        

• Unary minus - The symbol - is used to represent the unary plus operator. It does not change the operand value.

        a =  -1
        b = a //here b = -1
       

• Increment Operator - The symbol ++ is used to represent the increment operator. It can be used as a pre-increment or a post-increment operator. The pre-increment operator uses symbol ++i where value of operand i is increased by 1 before it is used. The post-increment operator uses symbol i++ where the value of operand i is increased by 1 after it is used.

The following program demonstrates the use of the increment operator:

        #include <iostream>
using namespace std;

int main()
{
    int i = 10;
    cout << "with post-increment i is " << i++ << "\n"; 
    cout << "After post-increment i is " << i << "\n";

    int j = 20;
    cout << "Before pre-increment j is " << j << "\n"; 
    cout << "with pre-increment j is " << ++j << "\n"; 
    return 0;
}
        

Output

with post-increment i is 10
After post-increment i is 11
Before pre-increment j is 20
with pre-increment j is 21

From the above example, we can understand that with ++j, the value of the variable i is incremented first and then it is used. In i++, the value of the variable is used first and then it is incremented. The decrement operator behaves in a similar way.

• Decrement Operator - The symbol -- is used to represent the increment operator. It can be used as a pre-decrement or a post-decrement operator. The pre-decrement operator uses the symbol --i where value of operand i is decreased by 1 before it is used. The post-decrement operator uses symbol i-- where the value of operand i is decreased by 1 after it is used.

The following program shows the use of the decrement operator:

        #include <iostream>
using namespace std;

int main()
{
    int i = 10;
    cout << "with post-decrement i is " << i-- << "\n"; 
    cout << "After post-decrement i is " << i << "\n";

    int j = 20;
    cout << "Before pre-decrement j is " << j << "\n"; 
    cout << "with pre-decrement j is " << ++j << "\n"; 
    return 0;
}
        

Output

with post-decrement i is 10
After post-decrement i is 9
Before pre-decrement j is 20
with pre-decrement j is 21
2. Binary Operators — Binary Operators are used with two operands to perform the arithmetic operations. Binary arithmetic operators are shown in the following table with examples:

Symbol	Name	Description	Example
+	Addition	Adds two operands.	int a = 3, b = 6; int c = a + b; // c = 9
-	Substraction	Substracts second operand from the first.	int a = 9, b = 6; int c = a - b; // c = 3
*	Multiplication	Multiplies two operands.	int a = 3, b = 6; int c = a * b; // c = 18
/	Division	Divides first operand by the second operand.	int a = 12, b = 6; int c = a / b; // c = 2
%	Modulo	Returns the remainder after the division of the first operand by the second operand.	int a = 8, b = 6; int c = a % b; // c = 2

The following program demonstrates the use of Binary Arithmetic operators in C++:

    #include <iostream>
using namespace std;

int main()
{
    int a = 8, b = 3;
    // Addition operator
    cout << "a + b = " << (a + b) << endl;

    // Subtraction operator
    cout << "a - b = " << (a - b) << endl;

    // Multiplication operator
    cout << "a * b = " << (a * b) << endl;

    // Division operator
    cout << "a / b = " << (a / b) << endl;

    // Modulo operator
    cout << "a % b = " << (a % b) << endl;

    return 0;
}

Output

a + b = 11
a - b = 5
a * b = 24
a / b = 2
a % b = 2

Assignment Operators

In C++, Assignment Operators are used to assign a value to a variable.

Assignment operators are shown in the following table with examples:

The following program demonstrates the use of Assignment Operators:

#include <iostream>
using namespace std;

int main()
{
    int a = 6, b = 4;

    // Assignment Operator
    cout << "a = " << a << endl;

    //  Add and Assignment Operator
    cout << "a += b is " << (a += b) << endl;

    // Subtract and Assignment Operator
    cout << "a -= b is " << (a -= b) << endl;

    //  Multiply and Assignment Operator
    cout << "a *= b is " << (a *= b) << endl;

    //  Divide and Assignment Operator
    cout << "a /= b is " << (a /= b) << endl;

    return 0;
}

Output

Relational Operators

Relational Operators are used when comparing the values of two operands. It is used when you need to know which operand is greater or which operand is less than the other. The result of using relation operator is always a Boolean value true or false.

The following table shows Relational operators with example in C++:

The following program demonstrates the use of Relational operators:

#include <iostream>
using namespace std;

int main()
{
    int a = 7, b = 3;
  
    // Equal to operator
    cout << "a == b is " << (a == b) << endl;
    
    // Greater than operator
    cout << "a > b is " << (a > b) << endl;
    
    // Greater than or Equal to operator
    cout << "a >= b is " << (a >= b) << endl;
    
    //  Lesser than operator
    cout << "a < b is " << (a < b) << endl;
    
    // Lesser than or Equal to operator
    cout << "a <= b is " << (a <= b) << endl;
    
    // true
    cout << "a != b is " << (a != b) << endl;
  
    return 0;
}

Output

Logical Operators

Logical operators are used to check whether a condition is true or false. If the condition is true, it returns 1 whereas if the condition is false, it returns 0.

Logical operators are shown in the following table with examples:

The following program demonstrates the use of Logical Operators:

#include <iostream>
using namespace std;

int main()
{
    int a = 6, b = 4;
  
    // Logical AND operator
    cout << "a && b is " << (a && b) << endl;
    
    // Logical OR operator
    cout << "a ! b is " << (a > b) << endl;
    
    // Logical NOT operator
    cout << "!b is " << (!b) << endl;
  
    return 0;
}

Output

Bitwise Operators

Bitwise Operators are used to perform bit-level operations on the operands. First, operators are converted to bit level then the calculation is performed on the operands. The arithmetic operations like addition, subtraction, multiplication, etc. can be done at the bit-level for faster processing.

The following table shows Relational operators with example in C++:

The following program demonstrates the use of Bitwise Operators in C++:

#include <iostream>
using namespace std;

int main()
{
    // bitwise NOT
    cout << "~" << "10" << " is " << ~10 << endl;

    // bitwise AND
    cout << "4" << " & " << "5" << " is " << (4 & 5) << endl;

    // bitwise OR
    cout << "4" << " | " << "5" << " is " << (4 | 5) << endl;

    // bitwise XOR
    cout << "4" << " ^ " << "5" << " is " << (4 ^ 5) << endl;

    // bitwise left shift
    cout << "4" << " << " << "2" << " is " << (4 << 2) << endl;

    // bitwise right shift
    cout << "4" << " >> " << "2" << " is " << (4 >> 2) << endl;

    return 0;
}

Output

Other Operators

Here is a list of some other common operators available in C++: