Operators in C

An operator is a symbol that tells the compiler to perform a specific operation on one or more operands (variables or values).

int sum = a + b;
// '+' is the operator; a and b are operands

Arithmetic Operators

Used to perform mathematical operations (assume a = 10, b = 3):

Operator	Name	Example	Result
`+`	Addition	`a + b`	`13`
`-`	Subtraction	`a - b`	`7`
`*`	Multiplication	`a * b`	`30`
`/`	Division	`a / b`	`3`
`%`	Modulus	`a % b`	`1`

/ performs integer division when both operands are integers (drops the decimal). % gives the remainder of that division.

Assignment Operators

Assign values to variables. The right-hand side is evaluated first, then assigned to the left.

int a = 10;           // simple assignment
int result = a + b;   // expression assigned to result

Chained assignment:

int a, b;
a = b = 20;   // b gets 20, then a gets b (both become 20)

Compound assignment:

a += 5;   // a = a + 5
a -= 3;   // a = a - 3
a *= 2;   // a = a * 2
a /= 4;   // a = a / 4
a %= 3;   // a = a % 3

Relational Operators

Compare two values. Result is 1 (true) or 0 (false). Assume a = 10, b = 5:

Operator	Description	Example	Result
`==`	Equal to	`a == b`	`0`
`!=`	Not equal to	`a != b`	`1`
`>`	Greater than	`a > b`	`1`
`<`	Less than	`a < b`	`0`
`>=`	Greater or equal	`a >= b`	`1`
`<=`	Less or equal	`a <= b`	`0`

Logical Operators

Combine multiple conditions:

Operator	Name	Meaning
`&&`	Logical AND	True if both are true
`\|\|`	Logical OR	True if either is true
`!`	Logical NOT	Inverts the condition

int age = 20, hasLicense = 1;
if (age >= 18 && hasLicense == 1)
    printf("Eligible to drive");

Bitwise Operators

Operate at the binary (bit) level:

Operator	Name	Description
`&`	AND	1 if both bits are 1
`\|`	OR	1 if either bit is 1
`^`	XOR	1 if bits differ
`~`	NOT	Flips all bits
`<<`	Left Shift	Shifts bits left
`>>`	Right Shift	Shifts bits right

Example:

int a = 12;   // binary: 01100
int b = 25;   // binary: 11001

printf("%d", a & b);   // 01000 = 8
printf("%d", a | b);   // 11101 = 29
printf("%d", a ^ b);   // 10101 = 21
printf("%d", a << 1);  // 11000 = 24 (shift left by 1)
printf("%d", a >> 1);  // 00110 = 6  (shift right by 1)

Increment / Decrement Operators

Operator	Type	Effect
`++a`	Pre-increment	Increment first, then use
`a++`	Post-increment	Use first, then increment
`--a`	Pre-decrement	Decrement first, then use
`a--`	Post-decrement	Use first, then decrement

int a = 5;
printf("%d", ++a);  // prints 6 (increments before print)
printf("%d", a++);  // prints 6 (prints then increments to 7)
printf("%d", a);    // prints 7

Practice Programs

Problem 1: Sum, Difference, Product, Quotient, Remainder

#include <stdio.h>
int main() {
    int a, b;
    printf("Enter two numbers: ");
    scanf("%d %d", &a, &b);
    printf("Sum       = %d\n", a + b);
    printf("Difference= %d\n", a - b);
    printf("Product   = %d\n", a * b);
    printf("Quotient  = %d\n", a / b);
    printf("Remainder = %d\n", a % b);
    return 0;
}

Problem 2: Average of Three Numbers

#include <stdio.h>
int main() {
    float a, b, c;
    printf("Enter three numbers: ");
    scanf("%f %f %f", &a, &b, &c);
    float avg = (a + b + c) / 3;
    printf("Average = %.2f", avg);
    return 0;
}

Problem 3: Convert Days into Years, Weeks, Days

#include <stdio.h>
int main() {
    int days, years, weeks, remaining;
    printf("Enter total days: ");
    scanf("%d", &days);
    years     = days / 365;
    weeks     = (days % 365) / 7;
    remaining = (days % 365) % 7;
    printf("Years: %d, Weeks: %d, Days: %d", years, weeks, remaining);
    return 0;
}

Problem 4: Check Even or Odd

#include <stdio.h>
int main() {
    int num;
    printf("Enter a number: ");
    scanf("%d", &num);
    if (num % 2 == 0)
        printf("Even");
    else
        printf("Odd");
    return 0;
}

Problem 5: Simple Interest Calculator

#include <stdio.h>
int main() {
    float p, r, t, si;
    printf("Enter Principal, Rate, Time: ");
    scanf("%f %f %f", &p, &r, &t);
    si = (p * r * t) / 100;
    printf("Simple Interest = %.2f", si);
    return 0;
}

Fundamentals

Functions

Array

String

Structure

Union

Pointer

File Handling

Preprocessor

Operators

Operators in C

Arithmetic Operators

Assignment Operators

Relational Operators

Logical Operators

Bitwise Operators

Increment / Decrement Operators

Practice Programs

​Operators in C

​Arithmetic Operators

​Assignment Operators

​Relational Operators

​Logical Operators

​Bitwise Operators

​Increment / Decrement Operators

​Practice Programs

Operators in C

Arithmetic Operators

Assignment Operators

Relational Operators

Logical Operators

Bitwise Operators

Increment / Decrement Operators

Practice Programs