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C program to find leap year using if else

Posted by: Instanceofjava Posted date: 10:42 PM / comment : 0 C language interview programs , c programming examples for beginners , c programming language

A year is said to be leap year if it is divisible by 4.
For example 2004 , 2008,2012 and 2016.
A year is also a leap year if it is divisible by 100 and divisible by 400.
For example 1600 and 2000 etc.
A leap year of February moth will have 29 days.
Let us see an example C program to check a year is leap year or not using simple if condition.
First we need to check a year is divisible by 4 or not.
If yes then again one more condition if it is divisible by 100 and 400. if it is divisible by 100 then it should be divisible by 400 then only it is leap year.
c program code to find leap year using if else

Program #1: Write a C program to check a year is leap year or not

#include <stdio.h>
#include <stdlib.h>
// Function to check if a year is a leap year
int isLeapYear(int year) {
// Logic for leap year:
// A year is a leap year if:
// 1. It is divisible by 4
// 2. If divisible by 100, it must also be divisible by 400
if (year % 4 == 0) {
if (year % 100 == 0) {
if (year % 400 == 0) {
// Year is divisible by 400
return 1; // It is a leap year
} else {
// Year is divisible by 100 but not by 400
return 0; // Not a leap year
}
} else {
// Year is divisible by 4 but not by 100
return 1; // It is a leap year
}
} else {
// Year is not divisible by 4
return 0; // Not a leap year
}
}
int main() {
// Program to check leap year in C programming
// Input year and output whether it is a leap year or not
int year; // Variable to store year input by user
printf("=== Leap Year Checker in C ===\n\n");
printf("This program checks if a given year is a leap year or not.\n\n");
// Prompt user for input
printf("Enter a year to check: ");
scanf("%d", &year);
// Call function to check leap year
if (isLeapYear(year)) {
printf("%d is a leap year!\n", year);
} else {
printf("%d is not a leap year.\n", year);
}
// Demonstrating the leap year logic with examples
printf("\nExamples of leap year logic:\n");
printf("- 2000: Divisible by 400, so it is a leap year.\n");
printf("- 1900: Divisible by 100 but not by 400, so not a leap year.\n");
printf("- 2016: Divisible by 4 but not by 100, so it is a leap year.\n");
printf("- 2019: Not divisible by 4, so not a leap year.\n\n");
// Prompt for additional checks
char choice;
do {
printf("Would you like to check another year? (y/n): ");
scanf(" %c", &choice);
if (choice == 'y' || choice == 'Y') {
printf("\nEnter a year to check: ");
scanf("%d", &year);
// Call function again for the new input
if (isLeapYear(year)) {
printf("%d is a leap year!\n", year);
} else {
printf("%d is not a leap year.\n", year);
}
}
} while (choice == 'y' || choice == 'Y');
printf("\nThank you for using the Leap Year Checker in C program!\n");
return 0;
}

Output:

=== Leap Year Checker in C ===
This program checks if a given year is a leap year or not.
Enter a year to check: 2000
2000 is a leap year!
Examples of leap year logic:
- 2000: Divisible by 400, so it is a leap year.
- 1900: Divisible by 100 but not by 400, so not a leap year.
- 2016: Divisible by 4 but not by 100, so it is a leap year.
- 2019: Not divisible by 4, so not a leap year.
Would you like to check another year? (y/n): n
Thank you for using the Leap Year Checker in C program!

Program #2: Write a C program to check a year is leap year or not without using any function.

#include <stdio.h>
#include <stdlib.h>
int main(){
int year;
printf("Enter a year to check if it is a leap year or not \n");
scanf("%d", &year);
if ( year%400 == 0)
printf("%d is a leap year.\n", year);
else if ( year%100 == 0)
printf("%d is not a leap year.\n", year);
else if ( year%4 == 0 )
printf("%d is a leap year.\n", year);
else
printf("%d is not a leap year.\n", year);
return 0;
}

Output:

C program to find sum of n numbers using for loop

Posted by: Instanceofjava Posted date: 6:54 PM / comment : 0 C language interview programs , c programming examples for beginners , c programming language

C program to find sum of n numbers using function
This is about to get sum of all natural numbers in C using for loop
For example 4: 1+2+3+4=11
Let us see an example program to get sum of natural numbers using while loop.
c program to find sum of n numbers using for loop

Program #1 : Write a C program to get sum of all natural numbers up to n using for loop

// www. instanceofjava.com all rights reserved
#include<stdio.h>
#include<math.h>
int main()
{
int n, i, sum = 0;
printf("Enter a positive integer: ");
scanf("%d",&n);
for(i=1; i <= n; ++i)
{
sum += i; // sum = sum+i;
}
printf("Sum = %d",sum);
return 0;
}

Output:

In this program, we first declare three variables: n, i, and sum. We use the printf function to prompt the user to enter the value of n, and the scanf function to read the value entered by the user and store it in the n variable.

The for loop iterates from 1 to n, and for each iteration, the current value of i is added to the sum variable. Once the loop completes, the final value of sum is the sum of the first n natural numbers.

The program then prints the final value of sum using the printf function.

You can try running this program and entering different values for n to see how it works.

Note: This program assumes that the input will be valid. You may want to include error check for non-integer input or negative number input.

C program to reverse a number using while loop and for loop

Posted by: Instanceofjava Posted date: 6:21 PM / comment : 0 C language interview programs , c programming examples for beginners

Finding reverse number means for example take 123 then we need to get 321 is its reverse number.
In c programming we can do it by using for loop and while loop.
Lets us see an example C program to get reverse number of a number by using while loop and for loop.
while(n != 0)
{
rem = n%10;
reverse_Number = reverse_Number*10 + rem;
n /= 10;
}

Program #1 : Write a c program to reverse number using for loop.

#include <stdio.h>
// www. instanceofjava.com all rights reserved
int main()
{
int n, reverse_Number = 0, rem,Original_number=0;
printf("Enter a number to get reverse number ");
scanf("%d", &n);
Original_number=n;
while(n != 0)
{
rem = n%10;
reverse_Number = reverse_Number*10 + rem;
n /= 10;
}
printf("Reversed Number of %d is = %d",Original_number=0;,reverse_Number);
getch();
}

Output:

Program #2 : Write a C program to reverse a number using for loop

#include <stdio.h>
// www. instanceofjava.com all rights reserved
int main()
{
int n, reverse_Number = 0, rem,Original_number=0;
printf("Enter a number to get reverse number ");
scanf("%d", &n);
Original_number=n;
for(;n != 0;)
{
rem = n%10;
reverse_Number = reverse_Number*10 + rem;
n /= 10;
}
printf("Reversed Number of %d is = %d",Original_number,reverse_Number);
getch();
}

Output:

Enter a number to get reverse number
123987
Reversed Number of 123987 is = 789321

C program to convert binary to decimal using for loop

Posted by: Instanceofjava Posted date: 5:58 PM / comment : 0 C language interview programs , c programming examples for beginners

c program to convert binary to decimal using array and for loop.
Lets us see an example program on c to convert binary format number to decimal format.
Write a function which accepts a number as binary.
rem = n%10;
n /= 10;
decimal += rem*pow(2,i);
This is the logic to get decimal format of the number.

Program #1 : write a c program to convert binary to decimal using while loop function

#include <stdio.h>
int convertBinaryToDecimal(long long n);
int main()
{
long long n;
printf("Enter a binary number: ");
scanf("%lld", &n);
printf("%lld binary format= %d decimal format", n, convertBinaryToDecimal(n));
getch();
}
int convertBinaryToDecimal(long long n)
{
int decimal = 0, i = 0, rem;
while (n!=0)
{
rem = n%10;
n /= 10;
decimal += rem*pow(2,i);
++i;
}
return decimal;
}

Output:

Program #2 : write a c program to convert binary to decimal using while loop function

#include <stdio.h>
int convertBinaryToDecimal(long long n);
int main()
{
long long n;
printf("Enter a binary number: ");
scanf("%lld", &n);
printf("%lld binary format= %d decimal format", n, convertBinaryToDecimal(n));
getch();
}
int convertBinaryToDecimal(long long n)
{
int decimal = 0, i = 0, rem;
for (i=0; n!=0;i++)
{
rem = n%10;
n /= 10;
decimal += rem*pow(2,i);
}
return decimal;
}

Output:

Enter a binary number:
1011
1011 binary format= 11 decimal format

C program to print multiplication table using while loop and for loop

Posted by: Instanceofjava Posted date: 5:40 PM / comment : 3 C language interview programs , c programming examples for beginners

C Program to Print Multiplication Table Using While Loop and For Loop

In the programming world, loops are the most basic. It is only by mastering the rules of a loop, and then replacing them with a loop when necessary, that we can program something that is reproducible. This article explores how to print a multiplication table in C using two types of loops: the `for` loop and the `while` loop. In fact, both approaches are often used—not only in commercial programming languages such as Basic but also in later ones like C. Both are also very simple and straightforward, helping you to consolidate your programming skills.

What is a Multiplication Table?

A multiplication table is a table used to define the multiplication operation for an algebraic system. Multiplying 5 by 1, 5 by 2, and so on—all ten answers to these multiplication problems make up the multiplication table of 5. One of the simplest forms is the multiplication table of 1—since 1 multiplied by any number always equals that same number. The product of a number and any of its factors is in this way called a "multiple." For example, multiply a circular disk by its diameter to get the circumference; the product of 3.14 and a disk with a diameter of 1 is 3.14.

Its is very easy to print multiplication table using c program
We need one for loop which iterates from 1 to 10
Inside for loop just multiply numbers and print result in each iteration.
Lets us see an example C program on how to print multiplication table using for loop.
multiplication table program in c using for loop
write a c program to input a number from user and print multiplication table of the given number using for loop. how to print multiplication table of a given number in c programming.

Program #1 : Write a c program to print multiplication table using for loop.Take input from user.

#include <stdio.h>
int main()
{
int n, i;
printf("Enter a Number ");
scanf("%d",&n);
for(i=1; i<=10; ++i)
{
printf("%d * %d = %d \n", n, i, n*i);
}
getch();
}

Output:

Program #2: Write a c program to print multiplication table using while loop

write a c program to print multiplication table of any number using for loop

#include <stdio.h>
int main()
{
int n, i;
printf("Enter a Number ");
scanf("%d",&n);
i=1;
while(i<=10){
printf("%d * %d = %d \n", n, i, n*i);
++i;
}
getch();
}

Output:

Enter a Number
2
2 * 1 = 2
2 * 2 = 4
2 * 3 = 6
2 * 4 = 8
2 * 5 = 10
2 * 6 = 12
2 * 7 = 14
2 * 8 = 16
2 * 9 = 18
2 * 10 = 20

Using a `while` Loop to Print a Multiplication Table

The `while` loop is a control flow statement that allows code to be executed repeatedly based on a given condition. If you want to print the multiplication table of a given number using a `while` loop, here is how you can do it in C:

#include <stdio.h>
int main() {
int number, i = 1;
// Input the number for which you want to print the multiplication table
printf("Enter a number: ");
scanf("%d", &number);
// Use a while loop to print the multiplication table
printf("Multiplication Table of %d using while loop:\n", number);
while (i <= 10) {
printf("%d x %d = %d\n", number, i, number * i);
i++;
}
return 0;
}

Explanation:

Input the Number: The program first asks the user to input a number for which the multiplication table will be generated.
Initialize `i`: The variable `i` is initialized to 1, which will act as the multiplicand.
While Loop Condition: As long as `i` is less than or equal to 10, the loop continues.
Print the Result: Within the loop, the program prints the result of `number * i`.
increment `i`: After each iteration, `i` is incremented by 1 to prepare for the next run.

Output Example:

Enter a number: 7
Multiplication Table of 7 using while loop:
7 x 1 = 7
7 x 2 = 14
7 x 3 = 21
7 x 4 = 28
7 x 5 = 35
7 x 6 = 42
7 x 7 = 49
7 x 8 = 56
7 x 9 = 63
7 x 10 = 70

Using a `for` Loop to Print a Multiplication Table

The `for` loop is another control flow statement providing a compact way to write loops. If you want to print the multiplication table of a number using a `for` loop, here is how you can do it in C:

#include <stdio.h>
int main() {
int number;
// Input the number for which you want to print the multiplication table
printf("Enter a number: ");
scanf("%d", &number);
// Use a for loop to print the multiplication table
printf("Multiplication Table of %d using for loop:\n", number);
for (int i = 1; i <= 10; i++) {
printf("%d x %d = %d\n", number, i, number * i);
}
return 0;
}

Explanation:

1. input the Number: Just as in the example with the `while` loop, this program first asks the user to input a number.

2. For Loop Initialization: The `for` loop initializes `i` to 1, checks the condition `i <= 10`, and increments `i` on each iteration.

3. Print the Result: The program prints the result of `number * i` inside the loop.

Output:

Enter a number: 7
Multiplication Table of 7 using for loop:
7 x 1 = 7
7 x 2 = 14
7 x 3 = 21
7 x 4 = 28
7 x 5 = 35
7 x 6 = 42
7 x 7 = 49
7 x 8 = 56
7 x 9 = 63
7 x 10 = 70

Key Differences Between a `while` Loop and a `for` Loop

Syntax: The syntax of the `for` loop is more succinct than that of the `while` loop. With the `for` loop, we can combine initialization, condition testing, and incrementation all into one line; whereas, in the `while` loop, these steps must be executed separately.

When to Use: Use a `while` loop when you don't know how many times the statement execution will be repeated. Use a `for` loop when you know the number of iterations in advance.

Both loops are powerful tools in the C language for handling repetitive work. By understanding how to use them to print a multiplication table, you can apply these methods to solve more complex problems in the future. Whether you choose a `while` loop or a `for` loop totally depends on your actual use case and coding style. I hope you have fun playing around with the code to understand the range of the multiplication table generated, or even combining the two loops under one program to enhance your understanding of them all. Happy programming!

C program to print prime numbers 1 to n

Posted by: Instanceofjava Posted date: 5:22 PM / comment : 0 C language interview programs , c programming examples for beginners

Any number which is divisible by 1 and itself is known as prime number.
To check prime number or not in c programming we need to use for loop and iterate from 2 to half of the number.
If any number is divisible then it is non prime number, we can exit the loop.
Now we need to check prime numbers from 1 to 100 or 1 to n.
Logic is same and we are adding one more for loop for 1 to N numbers.
Now we will iterate for loop from 1 to n and check prime or nor for each number.
Lets see an example program on c to check prime numbers from 1 to N.
Prime number program in c using for loop.
prime number program in c using while loop
prime number using while loop in c

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Program #1 : Write a c program to check prime numbers from 1 to N by using for loop.

prime number using for loop in c
C program to check prime number using while loop

#include <stdio.h>
int main()
{
int n, i,j, count = 0;
printf("Enter a Number");
scanf("%d",&n);
for(i=2;i<=n;i++)
{
for(j=2;j<i;j++)
{
if(i%j==0)
break;
else if(i==j+1)
printf("%d\n",i);
}
}
getch();
}

Output: