# Find first and last digits of a number

• Difficulty Level : Basic
• Last Updated : 21 Oct, 2022

Given a number to find first and last digit of a number.
Examples:

Input : 12345
Output : First digit: 1
last digit : 5

Input : 98562
Output : First digit: 9
last digit : 2

To find last digit of a number, we use modulo operator %. When modulo divided by 10 returns its last digit.
Suppose if n = 1234
then last Digit = n % 10 => 4
To find first digit of a number is little expensive than last digit. To find first digit of a number we divide the given number by 10 until number is greater than 10. At the end we are left with the first digit.

Approach 1 (With loop):

## C++

 // Program to find first and last// digits of a number#include using namespace std; // Find the first digitint firstDigit(int n){    // Remove last digit from number    // till only one digit is left    while (n >= 10)        n /= 10;         // return the first digit    return n;} // Find the last digitint lastDigit(int n){    // return the last digit    return (n % 10);} // Driver programint main(){    int n = 98562;    cout << firstDigit(n) << " "        << lastDigit(n) << endl;    return 0;}

## Java

 // Java Program to find first and last// digits of a numberimport java.util.*;import java.lang.*; public class GfG{         // Find the first digit    public static int firstDigit(int n)    {        // Remove last digit from number        // till only one digit is left        while (n >= 10)            n /= 10;             // return the first digit        return n;    }     // Find the last digit    public static int lastDigit(int n)    {        // return the last digit        return (n % 10);    }         // driver function    public static void main(String argc[])    {        int n = 98562;        System.out.println(firstDigit(n) + " "        + lastDigit(n));    }} // This code is contributed by Sagar Shukla

## Python3

 # Python3 program to find first and# last digits of a number # Find the first digitdef firstDigit(n) :     # Remove last digit from number    # till only one digit is left    while n >= 10:        n = n / 10;         # return the first digit    return int(n) # Find the last digitdef lastDigit(n) :     # return the last digit    return (n % 10) # Driver Coden = 98562;print(firstDigit(n), end = " ")print(lastDigit(n)) # This code is contributed by rishabh_jain

## C#

 // C# Program to find first and last// digits of a numberusing System; public class GfG{         // Find the first digit    public static int firstDigit(int n)    {        // Remove last digit from number        // till only one digit is left        while (n >= 10)            n /= 10;             // return the first digit        return n;    }     // Find the last digit    public static int lastDigit(int n)    {        // return the last digit        return (n % 10);    }         // driver function    public static void Main()    {        int n = 98562;        Console.WriteLine(firstDigit(n) + " "        + lastDigit(n));    }} // This code is contributed by vt_m

## PHP

 = 10)        \$n /= 10;         // return the first digit    return (int)\$n;} // Find the last digitfunction lastDigit(\$n){    // return the last digit    return ((int)\$n % 10);} // Driver Code\$n = 98562;echo firstDigit(\$n) . " " .     lastDigit(\$n) . "\n"; // This code is contributed// by Akanksha Rai(Abby_akku)

## Javascript



Output

9 2

Time Complexity: O(log10n)
Auxiliary Space: O(1)

Approach 2 (Without loop)

## C++

 // Program to find first and last// digits of a number#include using namespace std; // Find the first digitint firstDigit(int n){    // Find total number of digits - 1    int digits = (int)log10(n);     // Find first digit    n = (int)(n / pow(10, digits));     // Return first digit    return n;} // Find the last digitint lastDigit(int n){    // return the last digit    return (n % 10);} // Driver programint main(){    int n = 98562;    cout << firstDigit(n) << " "         << lastDigit(n) << endl;    return 0;}

## Java

 // Java program to find first and// last  digits of a numberimport java.math.*; class GFG {         // Find the first digit    static int firstDigit(int n)    {        // Find total number of digits - 1        int digits = (int)(Math.log10(n));             // Find first digit        n = (int)(n / (int)(Math.pow(10, digits)));             // Return first digit        return n;    }         // Find the last digit    static int lastDigit(int n)    {        // return the last digit        return (n % 10);    }         // Driver program    public static void main(String args[])    {        int n = 98562;        System.out.println(firstDigit(n) +                           " " + lastDigit(n));    }}  // This code is contributed by Nikita Tiwari.

## Python3

 # Python3 program to find first # and last digits of a numberimport math # Find the first digitdef firstDigit(n) :         # Find total number of digits - 1    digits = (int)(math.log10(n))     # Find first digit    n = (int)(n / pow(10, digits))     # Return first digit    return n; # Find the last digitdef lastDigit(n) :         # return the last digit    return (n % 10) # Driver Coden = 98562;print(firstDigit(n), end = " ")print(lastDigit(n)) # This code is contributed by rishabh_jain

## C#

 // C# program to find first and// last digits of a numberusing System; class GFG {         // Find the first digit    static int firstDigit(int n)    {        // Find total number of digits - 1        int digits = (int)(Math.Log10(n));             // Find first digit        n = (int)(n / (int)(Math.Pow(10, digits)));             // Return first digit        return n;    }         // Find the last digit    static int lastDigit(int n)    {        // return the last digit        return (n % 10);    }         // Driver program    public static void Main()    {        int n = 98562;        Console.WriteLine(firstDigit(n) +                        " " + lastDigit(n));    }}  // This code is contributed by vt_m.



## Javascript



Output

9 2

Time Complexity: O(1)
Auxiliary Space: O(1)

Important note: log10() is a mathematical function present in math.h header file. It returns log base 10 value of the passed parameter to log10() function.

My Personal Notes arrow_drop_up