In this article, you’ll learn how to reverse of a number in java language without giving input from the keyboard or giving input from the keyboard
In the above diagram, First, imagine the output screen
Enter a number:8614, if user write 4168 then our next step is to reverse the number that user enter and print on the screen in next line;
Reverse number: 4168
To reverse the number we create three variable x, r and initially y=0. We store the number enter by user users in x variable, and take one number from righthand side ( i.e.,8 in this program) and store in variable r, then from r store the number in variable y.
For doing the above process we follow the following step:
 x%10; it means 8614%10 gives remainder 4 and r=x%10; store the number 4 in variable r,
 y=r then from r variable the number 4 is stored in variable y which is initially 0. So y=4;
 x=x/10; it means 8614/10 then it gives the result i.e.,
again, repeat this process until x=0;
 now the new value of x=861
 x%10; it means 861%10 gives remainder 1 then store this number in variable r i.e.; r=x%10;
 when 2^{nd} time store the value of r in variable y, then multiply 10 by the previous value of y and add the value of r i.e.; y=10*y+r; put the value of y and r we get the new value of y. y=10*4+1; so new value of y=41
 x/10; it gives a new value of x that is 86
Repeat the above process until x=0. Then we find the reverse number of x that is stored in variable y and print the variable y to get the result.
Example 1: write a program in java to print a reverse of a number in java without giving input from keyboard
import java.util.Scanner;
public class ReadData { public static void main(String args[]) { int x=8614, y=0,r; while(x!=0) { r=x%10; y=y*10+r; x=x/10;} System.out.println(“Reverse Number= “+ y); } } 
The output of this program:
Reverse Number= 4168 
Example 2: write a program in java to print a reverse of a number, the input is given by the user from the keyboard.
Solution:
import java.util.Scanner;
public class ReverseNumber { public static void main(String args[]) { int y=0,r; System.out.print (“Enter two number: “); Scanner sc=new Scanner(System.in); int x=sc.nextInt(); while(x!=0) { r=x%10; y=y*10+r; x=x/10;} System.out.println(“Reverse Number= “+ y); } } 
The output of this program:
Enter two number: 8614 Reverse Number= 4168

Calculate L.C.M of two number in java language.