C Programming Language || Hands On Coding

💻 Check if Temperature is Freezing

#include <stdio.h>

int main() {
  int temperature;

  printf("Enter the temperature in Celsius: ");
  scanf("%d", &temperature);

  if (temperature <= 0) {
    printf("The temperature is freezing.n");
  } else {
    printf("The temperature is not freezing.n");
  }

  return 0;
}

📤 Output:

Input: -5
Output: The temperature is freezing.

Input: 25
Output: The temperature is not freezing.

Input: 0
Output: The temperature is freezing.

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💻 Check if Year is Leap Year

#include <stdio.h>

int main() {
    int year;

    printf("Enter a year: ");
    scanf("%d", &year);

    if (year % 4 == 0) {
        if (year % 100 == 0) {
            if (year % 400 == 0) {
                printf("%d is a leap year.n", year);
            } else {
                printf("%d is not a leap year.n", year);
            }
        } else {
            printf("%d is a leap year.n", year);
        }
    } else {
        printf("%d is not a leap year.n", year);
    }

    return 0;
}

📤 Output:

Input: 2024
Output: 2024 is a leap year.

Input: 2023
Output: 2023 is not a leap year.

Input: 1900
Output: 1900 is not a leap year.

Input: 2000
Output: 2000 is a leap year.

💻 Check if Point is at Origin

#include <stdio.h>

int main() {
  int x, y;

  printf("Enter the x-coordinate: ");
  scanf("%d", &x);

  printf("Enter the y-coordinate: ");
  scanf("%d", &y);

  if (x == 0 && y == 0) {
    printf("The point is at the origin.n");
  } else {
    printf("The point is not at the origin.n");
  }

  return 0;
}

📤 Output:

Input: 0
Input: 0
Output: The point is at the origin.

Input: 1
Input: 2
Output: The point is not at the origin.

💻 Check if Point Lies on Y-Axis

#include <stdio.h>

int main() {
  int x, y;

  printf("Enter the x-coordinate: ");
  scanf("%d", &x);

  printf("Enter the y-coordinate: ");
  scanf("%d", &y);

  if (x == 0) {
    printf("The point lies on the Y-axis.n");
  } else {
    printf("The point does not lie on the Y-axis.n");
  }

  return 0;
}

📤 Output:

Input: 0
Output: Enter the x-coordinate: Enter the y-coordinate: The point lies on the Y-axis.

Input: 5
Output: Enter the x-coordinate: Enter the y-coordinate: The point does not lie on the Y-axis.

💻 Check if Point Lies on X-Axis

#include <stdio.h>

int main() {
  float x, y;

  printf("Enter the x-coordinate: ");
  scanf("%f", &x);

  printf("Enter the y-coordinate: ");
  scanf("%f", &y);

  if (y == 0) {
    printf("The point lies on the X-axis.n");
  } else {
    printf("The point does not lie on the X-axis.n");
  }

  return 0;
}

📤 Output:

Input: 5.0
Input: 0.0
Output: The point lies on the X-axis.

Input: 2.5
Input: 3.7
Output: The point does not lie on the X-axis.

💻 Check if Character is Vowel

#include <stdio.h>
#include <ctype.h>

int main() {
    char ch;

    printf("Enter a character: ");
    scanf(" %c", &ch);

    ch = tolower(ch);

    if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
        printf("%c is a vowel.n", ch);
    } else {
        printf("%c is not a vowel.n", ch);
    }

    return 0;
}

📤 Output:

Input: A
Output: a is a vowel.

Input: b
Output: b is not a vowel.

Input: E
Output: e is a vowel.

Input: z
Output: z is not a vowel.

💻 Check if Number is Even

#include <stdio.h>

int main() {
    int number;

    printf("Enter an integer: ");
    scanf("%d", &number);

    if (number % 2 == 0) {
        printf("%d is even.n", number);
    } else {
        printf("%d is odd.n", number);
    }

    return 0;
}

📤 Output:

Input: 4
Output: 4 is even.

Input: 7
Output: 7 is odd.

Input: 0
Output: 0 is even.

Input: -2
Output: -2 is even.

Input: -5
Output: -5 is odd.

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💻 Check if Number is Positive

#include <stdio.h>

int main() {
    int num;

    printf("Enter a number: ");
    scanf("%d", &num);

    if (num > 0) {
        printf("The number is positive.n");
    }

    return 0;
}

📤 Output:

Input: 5
Output: Enter a number: The number is positive.

Input: -3
Output: Enter a number:

🔧 Conditional Statements - Simple if

💻 Swap First and Last Digits of a Number

#include <stdio.h>
#include <math.h>

int main() {
    int num, firstDigit, lastDigit, digits, tempNum, swappedNum;

    printf("Enter an integer: ");
    scanf("%d", &num);

    lastDigit = num % 10;
    tempNum = num;
    digits = 0;

    while (tempNum != 0) {
        tempNum /= 10;
        digits++;
    }

    firstDigit = num / pow(10, digits - 1);

    num -= firstDigit * pow(10, digits - 1);
    num += firstDigit;

    num -= lastDigit;
    num += lastDigit * pow(10, digits - 1);

    swappedNum = num;

    printf("Number after swapping first and last digit: %dn", swappedNum);

    return 0;
}

📤 Output:

Input: 12345
Output: Number after swapping first and last digit: 52341

Input: 678
Output: Number after swapping first and last digit: 876

Input: 9
Output: Number after swapping first and last digit: 9

Input: 2024
Output: Number after swapping first and last digit: 4022

💻 Seconds to Hours:Minutes:Seconds Converter

#include <stdio.h>

int main() {
  int totalSeconds, hours, minutes, seconds;

  printf("Enter the total number of seconds: ");
  scanf("%d", &totalSeconds);

  hours = totalSeconds / 3600;
  minutes = (totalSeconds % 3600) / 60;
  seconds = totalSeconds % 60;

  printf("Hours: %dn", hours);
  printf("Minutes: %dn", minutes);
  printf("Seconds: %dn", seconds);

  return 0;
}

📤 Output:

Input: 3661
Output: Enter the total number of seconds: Hours: 1
Minutes: 1
Seconds: 1

Input: 86400
Output: Enter the total number of seconds: Hours: 24
Minutes: 0
Seconds: 0

Input: 59
Output: Enter the total number of seconds: Hours: 0
Minutes: 0
Seconds: 59

💻 Calculate BMI (Body Mass Index)

#include <stdio.h>

int main() {
    float weight, height, bmi;

    printf("Enter weight in kilograms: ");
    scanf("%f", &weight);

    printf("Enter height in meters: ");
    scanf("%f", &height);

    bmi = weight / (height * height);

    printf("BMI = %.2fn", bmi);

    return 0;
}

📤 Output:

Input: 70
Input: 1.75
Output: BMI = 22.86

💻 Print Your Name, Age, and Hobby

#include <stdio.h>

int main() {
    char name[50];
    int age;
    char hobby[100];

    printf("Enter your name: ");
    scanf("%s", name);

    printf("Enter your age: ");
    scanf("%d", &age);

    printf("Enter your hobby: ");
    scanf(" %[^n]s", hobby);

    printf("Name: %sn", name);
    printf("Age: %dn", age);
    printf("Hobby: %sn", hobby);

    return 0;
}

📤 Output:

Input: John Doe
Input: 30
Input: Playing the guitar
Output: Enter your name: Enter your age: Enter your hobby: Name: John
Age: 30
Hobby: Playing the guitar

💻 Celsius to Fahrenheit Converter

#include <stdio.h>

int main() {
  float celsius, fahrenheit;

  printf("Enter temperature in Celsius: ");
  scanf("%f", &celsius);

  fahrenheit = (celsius * 9 / 5) + 32;

  printf("Temperature in Fahrenheit: %.2fn", fahrenheit);

  return 0;
}

📤 Output:

Input: 25
Output: Temperature in Fahrenheit: 77.00
Input: 0
Output: Temperature in Fahrenheit: 32.00
Input: -40
Output: Temperature in Fahrenheit: -40.00
Input: 100
Output: Temperature in Fahrenheit: 212.00

💻 Fahrenheit to Celsius Converter

#include <stdio.h>

int main() {
  float fahrenheit, celsius;

  printf("Enter temperature in Fahrenheit: ");
  scanf("%f", &fahrenheit);

  celsius = (fahrenheit - 32) * 5.0 / 9.0;

  printf("Temperature in Celsius: %.2fn", celsius);

  return 0;
}

📤 Output:

Input: 212
Output: Temperature in Celsius: 100.00

Input: 32
Output: Temperature in Celsius: 0.00

Input: 98.6
Output: Temperature in Celsius: 37.00

💻 Area of Rectangle Calculator

#include <stdio.h>

int main() {
    float length, width, area;

    printf("Enter the length of the rectangle: ");
    scanf("%f", &length);

    printf("Enter the width of the rectangle: ");
    scanf("%f", &width);

    area = length * width;

    printf("The area of the rectangle is: %fn", area);

    return 0;
}

📤 Output:

Input: 5.0
Input: 10.0
Output: The area of the rectangle is: 50.000000

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💻 Area of Circle Calculator

#include <stdio.h>

int main() {
    float radius, area;
    const float PI = 3.14159;

    printf("Enter the radius of the circle: ");
    scanf("%f", &radius);

    area = PI * radius * radius;

    printf("The area of the circle is: %fn", area);

    return 0;
}

📤 Output:

Input: 5
Output: Enter the radius of the circle: The area of the circle is: 78.539757

Input: 2.5
Output: Enter the radius of the circle: The area of the circle is: 19.634938