Java Program to print the first digit of a given number

Get input num and display the first digit of number num

Sample Input 1:

675

Sample Output 1:

The fisrt digit is :6

Program or Solution

				
			
					
import java.util.*;
class FirstDigit
{
  public static void main(String args[])
  {
        int num;
	Scanner sc=new Scanner(System.in);	
	System.out.println("Enter The Number:");
	num=sc.nextInt();
	while(num>=10)
	{
		num=num/10;
	}
	System.out.println("The First Digit Is:"+num);
  }
}
			
				
			

Program Explanation

1. Get num (to which first digit is to be identified)

2. Instruction(s) inside the while block{} are executed repeatedly till expression (num>=10) is true.

3. Divide the number num by 10 untill it becomes lesser than 10.

    once it is less than 10 print the num using system.out.println.

statement num = num/10 divides the num by 10 repeatedly until it num is less than 10


Example 

487

487/10 = 48

48 / 10 = 4

4 is less than 10, so print it.