Operators in C

Operators are special symbols used to perform operations on variables and values. These operations can be mathematical calculations, comparisons, logical checks, bit-level manipulations, and more.

The values or variables on which operators perform operations are called operands.

For example:

#include <stdio.h>

int main()
{
    int sum = 10 + 20;

    printf("%d", sum);

    return 0;
}

Output

In the above example, + is an operator and 10 and 20 are operands.

Unary, Binary, and Ternary Operators

Operators can be classified based on the number of operands they use.

Unary Operators

Unary operators work on a single operand.

Examples:

Increment (++)
Decrement (--)
Logical NOT (!)

Example:

int a = 10;
a++;

Binary Operators

Binary operators work on two operands.

Examples:

Addition (+)
Subtraction (-)
Multiplication (*)
Division (/)

Example:

int sum = 10 + 20;

Ternary Operators

Ternary operators work on three operands.

The conditional operator (?:) is the only ternary operator in C.

Example:

int result = (10 > 5) ? 1 : 0;

Types of Operators in C

C provides several types of operators:

Arithmetic Operators
Relational Operators
Logical Operators
Bitwise Operators
Assignment Operators
Special Operators

Arithmetic Operators

Arithmetic operators are used to perform mathematical calculations.

The most commonly used arithmetic operators are:

+ Addition
- Subtraction
* Multiplication
/ Division
% Modulus (Remainder)
++ Increment
-- Decrement

Example

#include <stdio.h>

int main()
{
    int a = 25, b = 5;

    printf("a + b = %d\n", a + b);
    printf("a - b = %d\n", a - b);
    printf("a * b = %d\n", a * b);
    printf("a / b = %d\n", a / b);
    printf("a %% b = %d\n", a % b);

    return 0;
}

Output

a + b = 30
a - b = 20
a * b = 125
a / b = 5
a % b = 0

Relational Operators

Relational operators are used to compare two values.

These operators always return:

1 (True)
0 (False)

Relational operators include:

< Less Than
> Greater Than
<= Less Than or Equal To
>= Greater Than or Equal To
== Equal To
!= Not Equal To

Example

#include <stdio.h>

int main()
{
    int a = 25, b = 5;

    printf("a > b = %d\n", a > b);
    printf("a < b = %d\n", a < b);
    printf("a == b = %d\n", a == b);

    return 0;
}

Output

a > b = 1
a < b = 0
a == b = 0

Logical Operators

Logical operators are used to combine multiple conditions.

The logical operators in C are:

Logical AND (&&)

Returns true only when both conditions are true.

a && b

Logical OR (||)

Returns true if at least one condition is true.

a || b

Logical NOT (!)

Reverses the result of a condition.

!a

Example

#include <stdio.h>

int main()
{
    int a = 25, b = 5;

    printf("a && b = %d\n", a && b);
    printf("a || b = %d\n", a || b);
    printf("!a = %d\n", !a);

    return 0;
}

Output

a && b = 1
a || b = 1
!a = 0

Bitwise Operators

Bitwise operators perform operations directly on binary bits.

Bitwise operators include:

& Bitwise AND
| Bitwise OR
^ Bitwise XOR
~ Bitwise NOT
<< Left Shift
>> Right Shift

Example

#include <stdio.h>

int main()
{
    int a = 25, b = 5;

    printf("a & b = %d\n", a & b);
    printf("a | b = %d\n", a | b);
    printf("a ^ b = %d\n", a ^ b);

    return 0;
}

Output

a & b = 1
a | b = 29
a ^ b = 28

Assignment Operators

Assignment operators are used to assign values to variables.

Simple Assignment Operator

a = b;

Compound Assignment Operators

a += b;
a -= b;
a *= b;
a /= b;
a %= b;

These operators perform an operation and assignment in a single step.

Example

#include <stdio.h>

int main()
{
    int a = 10;

    a += 5;
    printf("%d\n", a);

    return 0;
}

Output

sizeof Operator

The sizeof operator is used to determine the size of a variable or data type in bytes.

Example

#include <stdio.h>

int main()
{
    int num = 10;

    printf("%zu", sizeof(num));

    return 0;
}

Output

Comma Operator (,)

The comma operator allows multiple expressions to be evaluated in a single statement.

Example

int a, b;
a = 10, b = 20;

Conditional Operator (?:)

The conditional operator is a shorthand version of the if...else statement.

Syntax

condition ? expression1 : expression2;

Example

int result = (10 > 5) ? 100 : 200;

Output

Dot (.) and Arrow (->) Operators

These operators are used with structures.

Dot Operator

Used with a structure variable.

student.name

Arrow Operator

Used with a structure pointer.

ptr->name

Cast Operator

The cast operator is used to convert one data type into another.

Example

float num = 10.75;

printf("%d", (int)num);

Output

**Address-of (&) and Dereference (*) Operators**

These operators are commonly used with pointers.

Address-of Operator (&)

Returns the memory address of a variable.

int num = 10;

printf("%p", &num);

**Dereference Operator (*)**

Accesses the value stored at a memory address.

int num = 10;
int *ptr = &num;

printf("%d", *ptr);

Output

Summary

Operators are special symbols used to perform operations on variables and values.
The values on which operators work are called operands.
Operators are classified as unary, binary, and ternary operators.
Arithmetic operators perform mathematical calculations.
Relational operators compare values and return true or false.
Logical operators combine multiple conditions.
Bitwise operators work directly on binary bits.
Assignment operators assign values to variables.
Special operators such as sizeof, ?:, &, *, and type casting provide additional functionality in C.