Essential Guide to C Operators: Examples & Outputs Explained

Understanding operators in C is fundamental for anyone learning the language. This guide covers the various types of operators in C, complete with examples and their output, ensuring you have a solid grasp of their usage.

1. Arithmetic Operators in C

Arithmetic operators perform basic mathematical operations.

• Addition (+): Adds two operands.
• Subtraction (-): Deducts the second operand from the first.
• Multiplication (*): Multiplies two operands.
• Division (/): Performs division, yielding the quotient of the operands.
• Modulus (%): Computes the remainder after division of the numerator by the denominator.

Example:

#include <stdio.h>

int main() {
    int a = 10;
    int b = 3;
    printf("Addition: %d\n", a + b);
    printf("Subtraction: %d\n", a - b);
    printf("Multiplication: %d\n", a * b);
    printf("Division: %d\n", a / b); 
    printf("Modulus: %d\n", a % b);
    return 0;
}

Output:

Addition: 13
Subtraction: 7
Multiplication: 30
Division: 3
Modulus: 1

2. Relational Operators in C

Relational operators compare two values.

• Equal to (==)
• Not equal to (!=)
• Greater than (>)
• Less than (<)
• Greater than or equal to (>=)
• Less than or equal to (<=)

Example:

#include <stdio.h>

int main() {
    int x = 10;
    int y = 20;
    printf("\n x == y: %d\n", x == y);
    printf("\n x != y: %d\n", x != y);
    printf("\n x > y: %d\n", x > y);
    printf("\n x < y: %d\n", x < y);
    printf("\n x >= y: %d\n", x >= y);
    printf("\n x <= y: %d\n", x <= y);
    return 0;
}

Output:

x == y: 0
x != y: 1
x > y: 0
x < y: 1
x >= y: 0
x <= y: 1

3. Logical Operators in C

Logical operators are used for logical operations.

• Logical AND (&&)
• Logical OR (||)
• Logical NOT (!)

Example:

#include <stdio.h>

int main() {
    int a = 10;
    int b = 20;
    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 // 1 means true
a || b: 1
!a: 0// 0 means false

4. Bitwise Operators in C

Bitwise operators operate on bits and perform bit-by-bit operations.

• Bitwise AND (&)
• Bitwise OR (|)
• Bitwise XOR (^)
• Bitwise NOT (~)
• Left shift (<<)
• Right shift (>>)

Example:

#include <stdio.h>

int main() {
    int a = 5;    // Binary: 0101
    int b = 9;    // Binary: 1001
    printf("a & b: %d\n", a & b); 
    printf("a | b: %d\n", a | b);
    printf("a ^ b: %d\n", a ^ b); 
    printf("~a: %d\n", ~a); 
    printf("a << 1: %d\n", a << 1);
    printf("a >> 1: %d\n", a >> 1);
    return 0;
}

Output:

a & b: 1
a | b: 13
a ^ b: 12
~a: -6
a << 1: 10
a >> 1: 2

5. Assignment Operators in C

Assignment operators assign values to variables.

• Simple assignment (=)
• Add and assign (+=)
• Subtract and assign (-=)
• Multiply and assign (*=)
• Divide and assign (/=)
• Modulus and assign (%=)

Example:

#include <stdio.h>

int main() {
    int value = 10;
    value += 5;   // value = value + 5;  value is now 15
    printf("Value after += 5: %d\n", value);

    value -= 3;   // value = value - 3;  value is now 12
    printf("Value after -= 3: %d\n", value);

    value *= 2;   // value = value * 2;  value is now 24
    printf("Value after *= 2: %d\n", value);

    value /= 4;   // value = value / 4;  value is now 6
    printf("Value after /= 4: %d\n", value);

    value %= 5;   // value = value % 5;  value is now 1
    printf("Value after %= 5: %d\n", value);

    return 0;
}

Output:

Value after += 5: 15
Value after -= 3: 12
Value after *= 2: 24
Value after /= 4: 6
Value after %= 5: 1

6. Increment and Decrement Operators in C

These operators modify the value of a variable by incrementing or decrementing it by one.

• Increment (++)
• Decrement (--)

Example:

#include <stdio.h>

int main() {
    int a = 10;
    a++;   // a = a + 1;  a = 11
    printf("a after a++: %d\n", a);

    a--;   // a = a - 1;  a = 10
    printf("a after a--: %d\n", a);

    return 0;
}

Output:

a after a++: 11
a after a--: 10

7. Conditional (Ternary) Operator in C

The conditional operator evaluates a condition and returns one of two values accordingly.

• Ternary Operator (? :)

Example:

#include <stdio.h>

int main() {
    int a = 10;
    int b = 20;
    int max = (a > b) ? a : b;
    printf("Maximum value: %d\n", max);
    return 0;
}

Output:

Maximum value: 20

8. Sizeof Operator in C

The sizeof operator determines the memory size, in bytes, occupied by a data type or variable.

Example:

#include <stdio.h>

int main() {
    int a = 10;
    printf("Size of int: %lu\n", sizeof(int));
    printf("Size of a: %lu\n", sizeof(a));
    return 0;
}

Output:

Size of int: 4
Size of a: 4

9. Comma Operator in C

The comma operator enables the evaluation of several expressions within one statement, with the final expression's value being returned.

Example:

#include <stdio.h>

int main() {
    int a, b;
    a = (b = 5, b + 5); // b is assigned 5, then a is assigned b + 5
    printf("a: %d, b: %d\n", a, b);
    return 0;
}

Output:

a: 10, b: 5

These examples provide a comprehensive overview of the various operators in C, helping you understand their usage and functionality. Whether you're a newcomer or wanting to brush up on your skills, this guide includes all the key operators you'll find in C programming.