C Programs

Base Program to understand C programming

*Program to show any Written sentence

#include<stdio.h>

#include<conio.h>

void main()

{

printf(" Hello welcome to C Programming");

getch();

}

*Program to enter a number and display numbers:-

#include <stdio.h>
#include <conio.h>   
   int main() 
{   
    int number;
   
    printf("Enter an integer: ");  
    
    // reads and stores input
    scanf("%d", &number);

    // displays output
    printf("You entered: %d", number);
    getch();
    return 0;

}

*C Program to add two numbers:-

#include <stdio.h>
#include <conio.h>
    int main() 
   {    

    int number1, number2, sum;
    
    printf("Enter two integers: ");
    scanf("%d %d", &number1, &number2);

    // calculating sum
    sum = number1 + number2;      
    
    printf("%d + %d = %d", number1, number2, sum);
    getch();
    return 0;

}

*Program to Multiply Two Numbers

#include <stdio.h>
#include <conio.h>
int main() 
{
    double a, b, product;
    printf("Enter two numbers: ");
    scanf("%lf %lf", &a, &b);  

    // Calculating product
    product = a * b;

    // Result up to 2 decimal point is displayed using %.2lf
    printf("Product = %.2lf", product);
    getch();  
    return 0;

}

* Program to Print ASCII Value
#include <stdio.h>
#include <conio.h>
int main() 
{  
    char c;
    printf("Enter a character: ");
    scanf("%c", &c);  
    
    // %d displays the integer value of a character
    // %c displays the actual character
    printf("ASCII value of %c = %d", c, c);
    getch();
    return 0;
}

BY THIS METHOD YOU'LL GET ALL ASCII VALUES LIKE THIS :-

Enter a character: G
ASCII value of G = 71

In this program, the user is asked to enter a character. The character is stored in variable c.

When %d format string is used, 71 (the ASCII value of G) is displayed.


When %c format string is used, 'G' itself is displayed.

*Program to Compute Quotient and Remainder

#include <stdio.h>
#include <conio.h>
int main() 
{
    int dividend, divisor, quotient, remainder;
    printf("Enter dividend: ");
    scanf("%d", &dividend);
    printf("Enter divisor: ");
    scanf("%d", &divisor);

    // Computes quotient
    quotient = dividend / divisor;

    // Computes remainder
    remainder = dividend % divisor;

    printf("Quotient = %d\n", quotient);
    printf("Remainder = %d", remainder);
    getch();
    return 0;
}

*Program to Find the Size of Variables

#include<stdio.h>
#include<conio.h>
int main() 
{
    int intType;
    float floatType;
    double doubleType;
    char charType;

    // sizeof evaluates the size of a variable
    printf("Size of int: %ld bytes\n", sizeof(intType));
    printf("Size of float: %ld bytes\n", sizeof(floatType));
    printf("Size of double: %ld bytes\n", sizeof(doubleType));
    printf("Size of char: %ld byte\n", sizeof(charType));
    getch();    
    return 0;
}

*Swap Numbers Using Temporary Variable
#include<stdio.h>
#include<conio.h>
int main() 
{
      double first, second, temp;
      printf("Enter first number: ");
      scanf("%lf", &first);
      printf("Enter second number: ");
      scanf("%lf", &second);

      // Value of first is assigned to temp
      temp = first;

      // Value of second is assigned to first
      first = second;

      // Value of temp (initial value of first) is assigned to second
      second = temp;

      printf("\nAfter swapping, firstNumber = %.2lf\n", first);
      printf("After swapping, secondNumber = %.2lf", second);
      return 0;
}

*Program to Check Even or Odd

#include <stdio.h>
#include <conio.h>
int main() 
{
    int num;
    printf("Enter an integer: ");
    scanf("%d", &num);

    // True if num is perfectly divisible by 2
    if(num % 2 == 0)
        printf("%d is even.", num);
    else
        printf("%d is odd.", num);
    getch();    
    return 0;
}

*Program to Check Odd or Even Using the Ternary Operator

#include <stdio.h>
#include <conio.h>
int main() 
{
    int num;
    printf("Enter an integer: ");
    scanf("%d", &num);
    
    (num % 2 == 0) ? printf("%d is even.", num) : printf("%d is odd.", num);
    getch();
    return 0;
}

*Program to Check Vowel or consonant

#include <stdio.h>
#include <conio.h>
int main() 
{
    char c;
    int lowercase_vowel, uppercase_vowel;
    printf("Enter an alphabet: ");
    scanf("%c", &c);

    // evaluates to 1 if variable c is a lowercase vowel
    lowercase_vowel = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');

    // evaluates to 1 if variable c is a uppercase vowel
    uppercase_vowel = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');

    // evaluates to 1 (true) if c is a vowel
    if (lowercase_vowel || uppercase_vowel)
        printf("%c is a vowel.", c);
    else
        printf("%c is a consonant.", c);
    getch();
    return 0;
}

* C Program to Find the Largest Number Among Three Numbers

To understand this example, you should have the knowledge of the following C programming topics:

• C Programming Operators
• C if...else Statement

C if...else Statement

In this tutorial, you will learn about if statement (including if...else and nested if..else) in C programming with the help of examples.

C if Statement

The syntax of the if statement in C programming is:

if (test expression) 
{
   // statements to be executed if the test expression is true
}

How if statement works?

The if statement evaluates the test expression inside the parenthesis ().

If the test expression is evaluated to true, statements inside the body of if are executed.


If the test expression is evaluated to false, statements inside the body of if are not executed.




Example 1: if statement

// Program to display a number if it is negative

#include <stdio.h>
int main() 
{

    int number;

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

    // true if number is less than 0
    if (number < 0) {
        printf("You entered %d.\n", number);
    }

    printf("The if statement is easy.");

    return 0;
}

Output 1

Enter an integer: -2

You entered -2.

The if statement is easy.
When the user enters -2, the test expression number<0 is evaluated to true. Hence, You entered -2 is displayed on the screen.

Output 2

Enter an integer: 5

The if statement is easy.

When the user enters 5, the test expression number<0 is evaluated to false and the statement inside the body of if is not executed

C if...else Statement

The if statement may have an optional else block. The syntax of the if..else statement is:

if (test expression) 

{
    // statements to be executed if the test expression is true
}

else 

{
    // statements to be executed if the test expression is false
}

Example : Using if Statement

#include <stdio.h>
#include <conio.h>
int main() 
{
    double n1, n2, n3;
    printf("Enter three different numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    // if n1 is greater than both n2 and n3, n1 is the largest
    if (n1 >= n2 && n1 >= n3)
        printf("%.2f is the largest number.", n1);

    // if n2 is greater than both n1 and n3, n2 is the largest
    if (n2 >= n1 && n2 >= n3)
        printf("%.2f is the largest number.", n2);

    // if n3 is greater than both n1 and n2, n3 is the largest
    if (n3 >= n1 && n3 >= n2)
        printf("%.2f is the largest number.", n3);
    getch();
    return 0;

}

C Program to Find the Largest Number Among Three Numbers

Example 2: Using if...else Ladder

#include <stdio.h>
#include <conio.h>
int main() 
{
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    // if n1 is greater than both n2 and n3, n1 is the largest
    if (n1 >= n2 && n1 >= n3)
        printf("%.2lf is the largest number.", n1);

    // if n2 is greater than both n1 and n3, n2 is the largest
    else if (n2 >= n1 && n2 >= n3)
        printf("%.2lf is the largest number.", n2);

    // if both above conditions are false, n3 is the largest
    else
        printf("%.2lf is the largest number.", n3);
    getch();
    return 0;
}

C Program to Find the Largest Number Among Three Numbers

Example 3: Using Nested if...else

#include <stdio.h>
#include <conio.h>
int main() 
{
    double n1, n2, n3;
    printf("Enter three numbers: ");
    scanf("%lf %lf %lf", &n1, &n2, &n3);

    if (n1 >= n2) {
        if (n1 >= n3)
            printf("%.2lf is the largest number.", n1);
        else
            printf("%.2lf is the largest number.", n3);
    } else {
        if (n2 >= n3)
            printf("%.2lf is the largest number.", n2);
        else
            printf("%.2lf is the largest number.", n3);
    }
     getch();
    return 0;

}