Java Regex | HackerRank Solution

Hello coders, today we are going to solve Java Regex HackerRank Solution.

Java Regex


Write a class called MyRegex which will contain a string pattern. You need to write a regular expression and assign it to the pattern such that it can be used to validate an IP address. Use the following definition of an IP address:

IP address is a string in the form "A.B.C.D", where the value of A, B, C, and D may range from 0 to 255. Leading zeros are allowed. The length of A, B, C, or D can't be greater than 3.

Some valid IP address:

Some invalid IP address:

In this problem you will be provided strings containing any combination of ASCII characters. You have to write a regular expression to find the valid IPs.

Just write the MyRegex class which contains a String pattern. The string should contain the correct regular expression.

(MyRegex class MUST NOT be public)

Sample Input

Sample output


Solution – Java Regex

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Scanner;

class Solution{

    public static void main(String[] args){
        Scanner in = new Scanner(;
            String IP =;
            System.out.println(IP.matches(new MyRegex().pattern));


//Write your code here
     [01]?\\d{1,2}   matches numbers 0-199.
     2[0-4]\\d       matches numbers 200-249
     25[0-5]         matches numbers 250-255
class MyRegex {
    String num = "([01]?\\d{1,2}|2[0-4]\\d|25[0-5])";
    String pattern = num + "." +  num + "." +  num + "." + num;

Disclaimer: The above Problem ( Java Regex ) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.

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