In this post, we will learn** how to find the first and the last digit of a number using C** Programming language.

We will use following approaches to find the first and last digit of a number:

- Using Loop
- Without Using Loop
- Using Functions

So, without further ado, let’s begin this tutorial.

**C Program to Find First and Last Digit of a Number**

// C Program to Find First and Last Digit of a Number #include <stdio.h> int main(){ int num, firstDigit, lastDigit; // Asking for input printf("Enter a number: "); scanf("%d", &num); // Finding last digit of a number lastDigit = num % 10; // Finding first digit of a number firstDigit = num; while (firstDigit >= 10){ firstDigit = firstDigit / 10; } // Displaying output printf("First digit of the entered number is: %d \n", firstDigit); printf("Last digit of the entered number is: %d", lastDigit); return 0; }

**Output**

```
Enter a number: 247
First digit of the entered number is: 2
Last digit of the entered number is: 7
```

**How Does This Program Work?**

int num, firstDigit, lastDigit;

In this program, we have declared** three int data type** variables named **num**, **firstDigit** and** lastDigit**.

// Asking for input printf("Enter a number: "); scanf("%d", &num);

The user is asked to enter a positive number. This number gets stored in the **num** named variable.

// Finding last digit of a number lastDigit = num % 10;

We find the last digit of the entered number with the help of** (%)** Modulus operator. When the entered number is divided by **10**, then it returns the** remainder** which is the **last digit of a number**.

// Finding first digit of a number firstDigit = num; while (firstDigit >= 10){ firstDigit = firstDigit / 10; }

We find the first digit of the entered number with the help of **(/) **division operator. We divide the entered number by** 10** until the number is greater than **10**. When the number becomes less than **10**, we get the first digit.

// Displaying output printf("First digit of the entered number is: %d \n", firstDigit); printf("Last digit of the entered number is: %d", lastDigit);

At the end, the first and last digit of the entered number is printed on the screen using **printf() **function.

**C Program to Find First and Last Digit of a Number Without Using Loops**

// C Program to Find First and Last Digit of a Number Without Using Loops #include <stdio.h> int main(){ int num, firstDigit, lastDigit, count; // Asking for input printf("Enter a positive number: "); scanf("%d", &num); // Finding last digit lastDigit = num % 10; // Finding first digit count = (int)log10(num); firstDigit = (int)(num / pow(10, count)); // Displaying output printf("First Digit of the entered number is: %d \n", firstDigit); printf("Last Digit of the entered number is: %d", lastDigit); return 0; }

**Output**

```
Enter a positive number: 548
First Digit of the entered number is: 5
Last Digit of the entered number is: 8
```

**C Program to Find First and Last Digit of a Number Using Functions**

// C Program to Find First and Last Digit of a Number Using Functions #include <stdio.h> int first_digit(int n){ while (n >= 10){ n = n / 10; } return n; } int last_digit(int n){ return n % 10; } int main(){ int num, firstDigit, lastDigit; // Asking for input printf("Enter a number: "); scanf("%d", &num); // Calling out user-defined functions firstDigit = first_digit(num); lastDigit = last_digit(num); // Displaying output printf("The first digit of the entered number is: %d \n", firstDigit); printf("The last digit of the entered number is: %d", lastDigit); return 0; }

**Output**

```
Enter a number: 456
The first digit of the entered number is: 4
The last digit of the entered number is: 6
```

**Conclusion**

I hope after going through this post, you understand** how to find the first and the last digit of a number using C** Programming language.

If you have any doubt regarding the program, then contact us in the comment section. We will be delighted to solve your query.

**Also Read:**

**C Program to Calculate Electricity Bill****C Program to Calculate Potential Energy****C Program to Find First Digit of a Number****C Program to Find Area of Rhombus****C Program to Calculate Volume of Sphere**