Operators

Operators are symbols that perform operations on variables and values. For example, + is an operator used for addition, while - is an operator used for subtraction.

Operators in C++ can be classified into 6 types:

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

 

1. Arithmetic Operators

Arithmetic operators are used to perform arithmetic operations on variables and data. For example,

a + b;

Here, the + operator is used to add two variables a and b. Similarly there are various other arithmetic operators in C++.

Operator	Operation
+	Addition
-	Subtraction
*	Multiplication
/	Division
%	Modulo Operation (Remainder after division)

Example

#include <iostream>

using namespace std;

 

int main() {

    int a, b;

    a = 8;

    b = 2;

 

    // printing the sum of a and b

    cout << "a + b = " << (a + b) << endl;

 

    // printing the difference of a and b

    cout << "a - b = " << (a - b) << endl;

 

    // printing the product of a and b

    cout << "a * b = " << (a * b) << endl;

 

    // printing the division of a by b

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

 

    // printing the modulo of a by b

    cout << "a % b = " << (a % b) << endl;

 

    return 0;

}

Output

a + b = 10

a - b = 6

a * b = 16

a / b = 4

a % b = 0

 

Increment and Decrement Operators

C++ also provides increment and decrement operators: ++ and -- respectively.

• ++ increases the value of the operand by 1
• -- decreases it by 1

Example

#include <iostream>

using namespace std;

int main() {

    int a = 10, b = 100, result1, result2;

    // incrementing a by 1 and storing the result in result1

    result1 = ++a;

    cout << "result1 = " << result1 << endl;

// decrementing b by 1 and storing the result in result2  

    result2 = --b;

    cout << "result2 = " << result2 << endl;

 

    return 0;

}

Output

result1 = 11

result2 = 99

 

2. C++ Assignment Operators

In C++, assignment operators are used to assign values to variables. For example,

// assign 5 to a

  a=5;

Operator	Example	Equivalent to
=	a = b;	a = b;
+=	a += b;	a = a + b;
-=	a -= b;	a = a - b;
*=	a *= b;	a = a * b;
/=	a /= b;	a = a / b;
%=	a %= b;	a = a % b;

 

3. C++ Relational Operators

A relational operator is used to check the relationship between two operands. For example,

// checks if a is greater than b

a > b;

 

If the relation is true, it returns 1 whereas if the relation is false, it returns 0.

 

Operator	Meaning	Example
==	Is Equal To	3 == 5 gives us false
!=	Not Equal To	3 != 5 gives us true
>	Greater Than	3 > 5 gives us false
<	Less Than	3 < 5 gives us true
>=	Greater Than or Equal To	3 >= 5 give us false
<=	Less Than or Equal To	3 <= 5 gives us true

 

Note: Relational operators are used in decision-making and loops.

 

4. C++ Logical Operators

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

Operator	Example	Meaning
&&	expression1 && expression2	Logical AND. True only if all the operands are true.
||	expression1 || expression2	Logical OR. True if at least one of the operands is true.
!	!expression	Logical NOT. True only if the operand is false.

 

5. C++ Bitwise Operators

In C++, bitwise operators are used to perform operations on individual bits.

Operator	Description
&	Binary AND
|	Binary OR
^	Binary XOR
~	Binary One's Complement
<<	Binary Shift Left
>>	Binary Shift Right

The bitwise AND & operator returns 1 if and only if both the operands are 1. Otherwise, it returns 0.

Let's take a look at the bitwise AND operation of two integers 12 and 25:

12 = 00001100 (In Binary)

25 = 00011001 (In Binary)

//Bitwise AND Operation of 12 and 25

     00001100

&    00011001

     _________

     00001000  = 8 (In decimal)

 

The bitwise OR | operator returns 1 if at least one of the operands is 1. Otherwise, it returns 0.

Let us look at the bitwise OR operation of two integers 12 and 25:

12 = 00001100 (In Binary)

25 = 00011001 (In Binary)

Bitwise OR Operation of 12 and 25

    00001100

|   00011001

    _________

    00011101  = 29 (In decimal)

The bitwise XOR ^ operator returns 1 if and only if one of the operands is 1.

 However, if both the operands are 0, or if both are 1, then the result is 0.

Let us look at the bitwise XOR operation of two integers 12 and 25:

12 = 00001100 (In Binary)

25 = 00011001 (In Binary)

Bitwise XOR Operation of 12 and 25

    00001100

^   00011001

    _________

    00010101  = 21 (In decimal)

 

The bitwise complement operator is a unary operator (works on only one operand). It is denoted by ~ that changes binary digits 1 to 0 and 0 to 1.

6. C++ Right Shift Operator

The right shift operator shifts all bits towards the right by a certain number of specified bits. It is denoted by >>.

When we shift any number to the right, the least significant bits are discarded, while the most significant bits are replaced by zeroes.

 

7. C++ Left Shift Operator

The left shift operator shifts all bits towards the left by a certain number of specified bits. It is denoted by <<.

 

Example

Shift Right:

212 >> 0 = 212

212 >> 1 = 106

212 >> 2 = 53

212 >> 3 = 26

Shift Left:

212 << 0 = 212

212 << 1 = 424

212 << 2 = 848

212 << 3 = 1696

Other C++ Operators

Here's a list of some other common operators available in C++. We will learn about them in later tutorials.

Operator	Description	Example
sizeof	returns the size of data type	sizeof(int); // 4
?:	returns value based on the condition	string result = (5 > 0) ? "even" : "odd"; // "even"
&	represents memory address of the operand	# // address of num
.	accesses members of struct variables or class objects	s1.marks = 92;
->	used with pointers to access the class or struct variables	ptr->marks = 92;
<<	prints the output value	cout << 5;
>>	gets the input value	cin >> num;