# C program to check whether the number is odd or even

## Introduction

In this blog, we will discuss how to implement the odd or even program in c. first; we will try to understand the problem statement so that we can implement the program efficiently.

Once we are done with the problem statement, we will focus on the DRY run to understand the program's working.

But before we implement the program, let's discuss C programming.

Also see, __Binary to Hex Converter__

## What is C Language?

C programming language is one of the** oldest languages** in the programming community. C is a **mid-level language** means you can do **system programming **or **application programming **in C, which fills the gap between **low-level **and** high-level **languages. C is considered a good to learn programming language if you are a beginner because it will help clear the basic programming concepts necessary for a programmer.

### Features of C

- It is a
**robust programming language**with various**in-built functions, data types,**and**operators**.

- It is a
**platform-independent**means code written in C can be executed on any system.

- It is considered a
**fast programming language**.

- It is a procedural language.

Now, we know everything about the C programming language and its features. Next, let's see the problem statement in detail, which checks if a number is an odd or even number in C language. It is important to know the problem statement before implementing the odd or even program in c.

## Problem Statement

We must determine whether the given input number is odd or even in C.

To explain it, we need to check whether the given number is divisible by 2. If it is divisible by 2, then it is even; otherwise, it is odd.

**For example**, 2,4,10,8… are** even numbers** because they are **divisible by 2** and 3,5,9… are **odd numbers** because they are **not divisible by 2**.

### Example

Lets us understand the problem with an example, so we do not have remaining doubts and can easily understand the odd or even program in c and implement it on the Online C compiler.

**Sample Input**

4, 9

**Sample **Output

4 is an even number

9 is an odd number

**Explanation**

4%2 = 0 and 9%2 ≠ 0

## Approach

We will check if the number is odd or even in c by taking the **modulus ( % ) **of the number with 2.

Modulus gives the remainder** 0 **if the numerator is divisible by the denominator. In this case, the **numerator is user input**, and the** denominator is 2**. If the** remainder of the number modulus by 2 **is 0, then the number is even; otherwise, it is** odd**. The complete statement will look like the following.

`number%2==0`

Before we discuss the implementation, you need to know about the** conditional statements** in C because we have used conditional statements in the program.

Conditional statements, also known as an **if-else statements**, mean if a particular condition is true, then the program will run a statement, and if it is not true (else), then the program will execute the line of code written inside else.

You can also read about __dynamic array in c__.

## Dry Run

This DRY Run will help you to understand the functioning of the odd or even program in c. The following dice are the user input; you need to determine between them as odd or even.

To learn more about conditional statements, you can check the article below.

## Implementation

Now will discuss the two programs, each having different conditional statements to implement the odd or even program in c. the reason behind implementing the odd or even program in c with different conditional statements is to show that you can use any mathematical statement if it satisfies the odd or even conditions.

### Program 1

```
#include <stdio.h>
int main() {
int number;
/* taking the user input*/
printf("enter the number: ");
scanf("%d", & number);
/* checking if the number is divisible by 2*/
if (number % 2 == 0) {
/* printing the even number result*/
printf("%d is an even number", number);
}
else {
/* printing the odd number result*/
printf("%d is an odd number", number);
}
return 0;
```

**Output**

**Complexity**

Now, we will discuss the time complexity of the odd or even program in c.

**Time complexity**: The** time complexity will be O(1)** because we execute every program statement in O(1) times.

**Space Complexity**: The** space complexity will also be O(1)** because we are using only variables to store the user input.

**Now let's discuss the implementation of the odd or even program in c.**

- First, we take the
**input from the user**with the**scanf( )**method and store the input in the variable named**number.**

- After this, we apply the
**if-else statement**, and in the if statement, we check whether the**number%2==0**is true.

- If the statement is true, the given
**number is even**; otherwise, it will jump to the else statement, which prints that the**number is odd**.

### Program 2

You can use any condition in the if-else statement that satisfies the criteria of odd or even numbers. **For example**, if you use the** (number/2)*2 **condition and if this condition is equal to the **number variable.**

This will be even because the** / operator** gives the** divisor of the numbers**. So if you multiply the divisor again by 2, it will equal the number itself, which means it is even.

```
#include <stdio.h>
int main() {
int number;
/* taking the user input*/
printf("enter the number: ");
scanf("%d", & number);
/* checking if the number is even or not*/
if ( (number/2)*2 == number) {
/* printing the even number result*/
printf("%d is an even number", number);
}
else {
/* printing the odd number result*/
printf("%d is an odd number", number);
}
return 0;
}
```

**Output**

**Complexity**

Now, we will discuss the time complexity of the odd or even program in c.

**Time complexity**: The** time complexity will be O(1)** because we execute every program statement in O(1) times.

**Space Complexity**: The** space complexity will also be O(1)** because we are using only variables to store the user input.

## Frequently Asked Questions

### C is which type of language?

C is a mid-level language that can be used to implement system and application programming.

### Can I run my c program on different platforms or machines?

C programming language is platform-independent so that you can run your program on any system.

### Do I need to learn the C language as a beginner?

C language is considered foundational, but you can learn any language you want.

### Is C programming language a procedural language?

Yes, C is one of the oldest procedural programming languages.

### What does the modulus(%) of numbers return?

The modulus of two numbers returns the remainder of the numerator.

## Conclusion

In this blog, we learned how to differentiate between odd and even numbers. We have also learned how to implement the odd or even program in C. We have discussed conditional statements.

Check out the articles below to learn more about the C programming language.

__Difference between c and embedded c____C program to Count the Number of Vowels in a String____C program to delete vowels from a string____C program to multiply two numbers using plus operator____C Program to find frequency of characters__.

To learn more about DSA, __competitive coding__, and many more knowledgeable topics, please look into the __guided paths on Codestudio__. Also, you can enroll in our __courses__ and check out the __mock test__ and __problems __available to you. Please check out our __interview experiences __and __interview bundle__ for placement preparations.

Happy Coding!