Operators in C Programming

In C programming, operators are special symbols used to perform operations on variables and values. They form the backbone of expressions and are essential for writing logical, arithmetic, and decision-making programs.

Understanding operators in C language is crucial for beginners, exam preparation, and competitive programming.

What Are Operators in C?

An operator is a symbol that tells the compiler to perform a specific mathematical or logical operation.

Example:

int sum = a + b;

Here, + is an operator and a, b are operands.

Types of Operators in C Programming

C provides several types of operators, categorized based on their functionality.

Let’s explain all types one by one

1. Arithmetic Operators in C

Arithmetic operators in C are used to perform mathematical calculations.

Program: Arithmetic Operators in C

#include <stdio.h>
int main() {
int a = 10, b = 3;
printf("Addition (a + b): %d\n", a + b);
printf("Subtraction (a - b): %d\n", a - b);
printf("Multiplication (a * b): %d\n", a * b);
printf("Division (a / b): %d\n", a / b);
printf("Modulus (a % b): %d\n", a % b);
}

Output:

#include <stdio.h>

int main() {
int a = 5;
int b = 0;

printf("Unary plus (+a): %d\n", +a);
printf("Unary minus (-a): %d\n", -a);
printf("Pre-increment (++a): %d\n", ++a);
printf("Post-increment (a++): %d\n", a++);
printf("After post-increment a: %d\n", a);
printf("Pre-decrement (--a): %d\n", --a);
printf("Post-decrement (a--): %d\n", a--);
printf("After post-decrement a: %d\n", a);
printf("Logical NOT (!b): %d\n", !b);
printf("Bitwise NOT (~a): %d\n", ~a);
printf("Size of int: %lu bytes\n", sizeof(int));

float f;
int *p;
p = &a;
printf("Address of a (&a): %p\n", &a);
printf("Value using pointer (*p): %d\n", *p);
f = (float)a;
printf("Type casting int to float: %.2f\n", f);

return 0;
}

Output:

3. Relational Operators in C

Relational operators are used to compare two operands. They return 1 (true) if the condition is true and 0 (false) if the condition is false.

Relational Operators Table

Program: Relational Operators in C

#include <stdio.h>
int main() {
int a = 10, 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);
printf("a <= b: %d\n", a <= b);

return 0;
}

Output

4. Logical Operators in C

Logical operators are used to combine or invert relational expressions. They return 1 (true) or 0 (false).

Logical Operators Table

Program: Logical Operators in C

#include <stdio.h>

int main() {
int a = 10, b = 5, c = 0;

printf("(a > b && b > c): %d\n", (a > b && b > c));
printf("(a > b || b < c): %d\n", (a > b || b < c));
printf("!(a > b): %d\n", !(a > b));
printf("!(c): %d\n", !c);

return 0;
}

Output

5. Assignment Operators in C

Assignment operators are used to assign values to variables. They can also perform an operation and an assignment in a single step.

Assignment Operators Table

#include <stdio.h>

int main() {
int a = 10;

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

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

a -= 3;
printf("a -= 3, the answer is %d\n", a);

a *= 2;
printf("a *= 2, the answer is %d\n", a);

a /= 4;
printf("a /= 4, the answer is %d\n", a);

a %= 3;
printf("a %= 3, the answer is %d\n", a);

a <<= 1;
printf("a <<= 1, the answer is %d\n", a);

a >>= 1;
printf("a >>= 1, the answer is %d\n", a);

a &= 1;
printf("a &= 1, the answer is %d\n", a);

a |= 2;
printf("a |= 2, the answer is %d\n", a);

a ^= 3;
printf("a ^= 3, the answer is %d\n", a);

return 0;
}

6. Bitwise Operators in C

Bitwise operators work on individual bits of integer data types. They are mainly used in low-level programming, embedded systems, and performance-critical code.

Bitwise Operators Table

Program: Bitwise Operators in C

#include <stdio.h>

int main() {
int a = 5, b = 3;

printf("a & b, the answer is %d\n", a & b);
printf("a | b, the answer is %d\n", a | b);
printf("a ^ b, the answer is %d\n", a ^ b);
printf("~a, the answer is %d\n", ~a);
printf("a << 1, the answer is %d\n", a << 1);
printf("a >> 1, the answer is %d\n", a >> 1);

return 0;
}

Output

7. Conditional (Ternary) Operator in C

The conditional (ternary) operator is used to make decisions in a single line. It is a short form of the if–else statement.

Conditional Operator Table

Syntax

• If condition is true (1) → expression1 is executed

• If condition is false (0) → expression2 is executed

Program: Conditional (Ternary) Operator in C (with Output)

#include <stdio.h>

int main() {
int a = 10, b = 20;
int max;

max = (a > b) ? a : b;
printf("Maximum value, the answer is %d\n", max);

int num = 7;
char result;

result = (num % 2 == 0) ? 'E' : 'O';
printf("Number is Even or Odd, the answer is %c\n", result);

return 0;
}

Output

8. Special Operators in C

#include <stdio.h>

struct Student {
int id;
int marks;
};

int main() {
int a = 10, b = 20;
int *p;
struct Student s;
struct Student *ps;

/* sizeof operator */
printf("Size of int, the answer is %lu\n", sizeof(int));

/* comma operator */
a = (b = 5, b + 10);
printf("Comma operator result, the answer is %d\n", a);

/* address and pointer operators */
p = &a;
printf("Address of a, the answer is %p\n", &a);
printf("Value using pointer, the answer is %d\n", *p);

/* conditional operator */
printf("Greater value, the answer is %d\n", (a > b) ? a : b);

/* structure operators */
s.id = 1;
s.marks = 90;
printf("Structure dot operator, the answer is %d\n", s.marks);

ps = &s;
printf("Structure arrow operator, the answer is %d\n", ps->marks);

/* array subscript */
int arr[3] = {10, 20, 30};
printf("Array element arr[1], the answer is %d\n", arr[1]);

return 0;
}

Operator Precedence in C Programming

Operator precedence determines the order in which operators are evaluated in an expression.
If operators have the same precedence, associativity decides the evaluation order.

Tip: Use parentheses to avoid confusion.

Why Operators Are Important in C?

 Build expressions
 Control program flow
 Perform calculations
 Essential for algorithms and data structures

Conclusion

Operators in C programming are fundamental tools that allow programmers to perform computations, make decisions, and manipulate data efficiently. Mastering operator types and precedence helps write error-free and optimized C programs.