In his tutorial, we will learn how to write a java program to check bouncy number. Before we code, let us understand what is a bouncy number.

**Bouncy Number**

A number is said to be a bouncy number if the digits of that number are in random order that is not sorted. Example: 121575, 521634, etc.

In other words, a number that is neither an increasing number nor a decreasing number is called a bouncy number.

**Increasing number:**The number whose current digit is greater than or equal to the previous digit is called an increasing number. Example: 12345, 45678, etc.**Decreasing number:**The number whose current digit is less than the previous digit is called an decreasing number. Example: 54321, 98765, etc.

**Bouncy Number Program in Java**

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 | import java.util.*; public class Main { public static void main(String args[]) { int num; Scanner scan = new Scanner(System.in); System.out.print("Enter the number: "); num = scan.nextInt(); //calling function and checking condition if (isIncreasing(num) || isDecreasing(num) || num < 101) System.out.println(num + " is NOT a Bouncy number"); else System.out.println(num + " is a Bouncy number"); } //user-defined function to check for incresing number public static boolean isIncreasing(int num) { String str = Integer.toString(num); char digit; boolean flag = true; for (int i = 0; i < str.length() - 1; i++) { digit = str.charAt(i); if (digit > str.charAt(i + 1)) { flag = false; break; } } return flag; } //user-defined function to check for decreasing number public static boolean isDecreasing(int num) { String str = Integer.toString(num); char digit; boolean flag = true; for (int i = 0; i < str.length() - 1; i++) { digit = str.charAt(i); if (digit < str.charAt(i + 1)) { flag = false; break; } } return flag; } } |

**Output:**

`//Run 1`

Enter the number: 12345

12345 is NOT a Bouncy number

//Run2

Enter the number: 23561

23561 is a Bouncy number