C Program to Check Even Number

Posted in C Tutorial

Updated on Jan 10, 2024

By Mari Selvan

👁️ 206 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, dealing with numbers is a fundamental task. One common requirement is checking whether a given number is even or not. An even number is an integer that is exactly divisible by 2 without leaving a remainder.

In this tutorial, we will explore a C program designed to check whether a given number is even. The program involves using the modulo operator to determine if the number is divisible by 2.

📄 Example

Let's delve into the C code that accomplishes this task.

isEven.c

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#include <stdio.h>

// Function to check if a number is even
int isEven(int number) {
  // If the remainder is zero, the number is even
  return number % 2 == 0;
}

// Driver program
int main() {
  // Replace this value with the number you want to check
  int number = 10;

  // Call the function to check if the number is even
  if (isEven(number))
    printf("%d is an even number.\n", number);
  else
    printf("%d is not an even number.\n", number);

  return 0;
}

💻 Testing the Program

To test the program with different numbers, modify the value of number in the main program.

Output

10 is an even number.

🧠 How the Program Works

The program defines a function isEven that takes an integer number as input and returns 1 (true) if the number is even, and 0 (false) otherwise.
Inside the main program, replace the value of number with the desired number you want to check.
The program calls the isEven function and prints the result.

📏 Between the Given Range

Let's delve into the C code that accomplishes the task.

isEven.c

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#include <stdio.h>

// Function to check if a number is even
int isEven(int num) {
  return (num % 2 == 0);
}

// Function to check even numbers in a range
void checkEvenNumbersInRange(int start, int end) {
  printf("Even numbers in the range %d to %d:\n", start, end);

  for (int i = start; i <= end; ++i) {
    if (isEven(i)) {
      printf("%d ", i);
    }
  }

  printf("\n");
}

// Driver program
int main() {
  // Range of numbers
  int start = 1;
  int end = 10;

  // Call the function to check even numbers in the range
  checkEvenNumbersInRange(start, end);

  return 0;
}

💻 Testing the Program

Output

Even numbers in the range 1 to 10:
2 4 6 8 10

Compile and run the program to see the even numbers in the specified range.

🧠 How the Program Works

The program defines a function isEven that checks whether a given number is even.
It then defines a function checkEvenNumbersInRange that prints even numbers within a specified range.
The main function sets the range from 1 to 10 and calls the function to check even numbers.