JAVA PROGRAM TO REVERSE A GIVEN NUMBER
In this module we will learn about how to reverse a given number with multiple solutions
Table of Contents
[hide]- Java Program to Reverse a Given Number Using while Loop
- Java Program to Reverse a Given Number Using while Loop(another way)
- Java Program to Reverse a Given Number Using for Loop
- Java Program to Reverse a Given Number Using recursion
Example 1 : Java Program to Reverse a Given Number Using while Loop
Algorithm
Take input from the user and store it in variable name num.
Pass this number to a method name reverse() which we can acces by the obj of ReverseDemo class.
A while loop is being used to iterate the text expression until n!=0
A variable name digit store the mod of n and 10 which is the last number of n.
Once we have stored the last number in the variable digit then we will divide the n with 10, so as to perform the same operation with the remaining numbers.
We keep on printing the last digit inside the while loop until n!=0 and while loop exits.
// Java Program to reverse a given number
import java.util.Scanner;
class ReverseDemo{
public void reverse(int n){
while(n!=0) {
int digit=n%10;
n=n/10;
System.out.println(digit);
}
}
}
public class Codebator{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("Enter any number");
int num = sc.nextInt();
ReverseDemo obj=new ReverseDemo();
obj.reverse(num);
}
}
OUTPUT :
Enter any number34567 76543
Example 2 : Java Program to Reverse a Given Number Using while Loop(another way)
// Java Program to reverse a given number
import java.util.Scanner;
class ReverseDemo{
public void reverse(int n){
int rev=0;
while(n!=0) {
int digit=n%10;
rev=rev*10+digit;
n=n/10;
}
System.out.println(rev);
}
}
public class Codebator{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("Enter any number");
int num = sc.nextInt();
ReverseDemo obj=new ReverseDemo();
obj.reverse(num);
}
}
OUTPUT :
Enter any number12345 54321
Example 3 : Java Program to Reverse a Given Number Using for loop
// Java Program to reverse a given number using for loop
import java.util.Scanner;
class ReverseDemo{
public void reverse(int n){
for(;n!=0;n=n/10) {
int digit=n%10;
System.out.print(digit);
}
}
}
public class Codebator{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("Enter any number");
int num = sc.nextInt();
ReverseDemo obj=new ReverseDemo();
obj.reverse(num);
}
}
OUTPUT :
Enter any number45678 87654
Example 4 : Java Program to Reverse a Given Number Using Recursion
// Java Program to reverse a given number using recursion
import java.util.Scanner;
class ReverseDemo{
public void reverse(int n){
if(n<10) {
System.out.print(n);
}
else {
System.out.print(n%10);
reverse(n/10);
}
}
}
public class Codebator{
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("Enter any number");
int num = sc.nextInt();
ReverseDemo obj=new ReverseDemo();
obj.reverse(num);
}
}
OUTPUT :
Enter any number9876 6789
