Validating UPI IDs using Regular Expressions ❤️

Given some UPI IDs, the task is to check if they are valid or not using regular expressions. Rules for the valid UPI ID:

UPI ID is an alphanumeric String i.e., formed using digits(0-9), alphabets (A-Z and a-z), and other special characters.
It must contain ‘@’.
It should not contain whitespace.
It may or may not contain a dot (.) or hyphen (-).

UPI stands for Unified Payments Interface (UPI).UPI IDs are unique IDs given to each customer.

Examples :

Input: str = ”9136812895@ybl?
Output: True

Input: str = ”MH05DL9023 ”
Output: false
Explanation: It does not contain the “@” symbol.

Input: str = ”ViratKohli101@paytm?
Output: true

Input: str =”rahul.12chauhan1998-1@okicici?
Output: true

Input: str = ”1234567890@upi123456?
Output: true

Input: str = ”Akanksha @ybl ”
Output: false
Explanation: It contains a whitespace.

Approach: The problem can be solved based on the following idea:

Create a regex pattern to validate the number as written below:
regex=”^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$”

^ : Beginning of the string.
[] Character set :Match any character in the set.
[a-zA-Z0-9.-] : Match any character in the range a-z, A-Z, 0-9, hyphen(-), dot(.).
{2, 256} Quantifier: Match between 2 and 256 of the preceding items.
$: End of the string

Follow the below steps to implement the idea:

Create regex expression for UPI ID.
Use Pattern class to compile the regex formed.
Use the matcher function to check whether the UPI id is valid or not.
If it is valid, return true. Otherwise, return false.

Below is the implementation of the above approach.

C++

// C++ program to validate the
// UPI ID using Regular
// Expression
 
#include <bits/stdc++.h>
#include <regex>
using namespace std;
 
// Function to validate the
// upi_Id Code
string isValidUpi(string upi_Id)
{
    // Regex to check valid upi_Id Code
    const regex pattern(
        "^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$");
 
    // If the upi_Id Code
    // is empty return false
    if (upi_Id.empty()) {
        return "false";
    }
 
    // Return true if the upi_Id Code
    // matched the ReGex
    if (regex_match(upi_Id, pattern)) {
        return "true";
    }
    else {
        return "false";
    }
}
 
// Driver Code
int main()
{
    // Test Case 1:
    string str1 = "9136812895@ybl";
    cout << isValidUpi(str1) << endl;
 
    // Test Case 2:
    string str2 = "rahul.12chauhan1998-1@okicici";
    cout << isValidUpi(str2) << endl;
 
    // Test Case 3:
    string str3 = "BNZAA2318JM";
    cout << isValidUpi(str3) << endl;
 
    // Test Case 4:
    string str4 = "934517865";
    cout << isValidUpi(str4) << endl;
 
    // Test Case 5:
    string str5 = "ViratKohli101@paytm";
    cout << isValidUpi(str5) << endl;
 
    // Test Case 6:
    string str6 = "Akanksha  @ybl";
    cout << isValidUpi(str6) << endl;
 
    return 0;
}

Java

// Java program to validate the
// UPI ID using Regular Expression
 
import java.util.regex.*;
 
class GFG {
    // Function to validate the
    // UPI ID(For India Country Only)
    public static boolean isValidUpi(String upi_Id)
    {
 
        // Regex to check valid upi_Id Code
        String regex
            = "^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$";
 
        // Compile the ReGex
        Pattern p = Pattern.compile(regex);
 
        // If the upi_Id Code
        // is empty return false
        if (upi_Id == null) {
            return false;
        }
 
        // Pattern class contains matcher()
        // method to find matching between
        // given MICR Code using regex
        Matcher m = p.matcher(upi_Id);
 
        // Return if the upi_Id Code
        // matched the ReGex
        return m.matches();
    }
 
    // Driver Code.
    public static void main(String args[])
    {
 
        // Test Case 1:
        String str1 = "9136812895@ybl";
        System.out.println(isValidUpi(str1));
 
        // Test Case 2:
        String str2 = "rahul.12chauhan1998-1@okicici";
        System.out.println(isValidUpi(str2));
 
        // Test Case 3:
        String str3 = "BNZAA2318JM";
        System.out.println(isValidUpi(str3));
 
        // Test Case 4:
        String str4 = "934517865";
        System.out.println(isValidUpi(str4));
 
        // Test Case 5:
        String str5 = "ViratKohli101@paytm";
        System.out.println(isValidUpi(str5));
 
        // Test Case 6:
        String str6 = "Akanksha  @ybl";
        System.out.println(isValidUpi(str6));
    }
}

Python3

# Python3 program to validate
# UPI ID  using Regular Expression
 
import re
 
# Function to validate
# UPI ID(For India Country Only)
def isValidUpi(str):
 
    # Regex to check valid UPI ID
    regex = "^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$"
 
    # Compile the ReGex
    p = re.compile(regex)
 
    # If the string is empty
    # return false
    if (str == None):
        return False
 
    # Return if the string
    # matched the ReGex
    if(re.search(p, str)):
        return True
    else:
        return False
 
 
# Driver code
if __name__ == '__main__':
     
    # Test Case 1:
    str1 = "9136812895@ybl"
    print(isValidUpi(str1))
     
    # Test Case 2:
    str2 = "rahul.12chauhan1998-1@okicici"
    print(isValidUpi(str2))
     
    # Test Case 3:
    str3 = "Rahul 1998"
    print(isValidUpi(str3))
     
    # Test Case 4:
    str4 = "934517865"
    print(isValidUpi(str4))
     
    # Test Case 5:
    str5 = "ViratKohli101@paytm"
    print(isValidUpi(str5))
     
    # Test Case 6:
    str6 = "Akanksha  @ybl"
    print(isValidUpi(str6))

C#

// C# program to validate the
// UPI ID using Regular Expression
using System;
using System.Text.RegularExpressions;
 
public class GFG 
{
   
  // Function to validate the
  // UPI ID(For India Country Only)
  public static bool isValidUpi(string upi_Id)
  {
 
    // Regex to check valid upi_Id Code
    string regex
      = "^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$";
 
    // Compile the ReGex
    Regex p = new Regex(regex);
 
    // If the upi_Id Code
    // is empty return false
    if (upi_Id == null) {
      return false;
    }
 
    // Pattern class contains matcher()
    // method to find matching between
    // given MICR Code using regex
    Match m = p.Match(upi_Id);
 
    // Return if the upi_Id Code
    // matched the ReGex
    return m.Success;
  }
 
  // Driver Code.
  public static void Main()
  {
 
    // Test Case 1:
    string str1 = "9136812895@ybl";
    Console.WriteLine(isValidUpi(str1));
 
    // Test Case 2:
    string str2 = "rahul.12chauhan1998-1@okicici";
    Console.WriteLine(isValidUpi(str2));
 
    // Test Case 3:
    string str3 = "BNZAA2318JM";
    Console.WriteLine(isValidUpi(str3));
 
    // Test Case 4:
    string str4 = "934517865";
    Console.WriteLine(isValidUpi(str4));
 
    // Test Case 5:
    string str5 = "ViratKohli101@paytm";
    Console.WriteLine(isValidUpi(str5));
 
    // Test Case 6:
    string str6 = "Akanksha @ybl";
    Console.WriteLine(isValidUpi(str6));
  }
}
 
// This code is contributed by Pushpesh Raj.

Javascript

// Javascript program to validate
// UPI ID  using Regular Expression
 
// Function to validate the
// upi_Id Code  
function isValid_UPI_ID(upi_Id) {
    // Regex to check valid
    // upi_Id
    let regex = new RegExp(/^[a-zA-Z0-9.-]{2, 256}@[a-zA-Z][a-zA-Z]{2, 64}$/);
 
    // upi_Id
    // is empty return false
    if (upi_Id == null) {
        return "false";
    }
 
    // Return true if the upi_Id
    // matched the ReGex
    if (regex.test(upi_Id) == true) {
        return "true";
    }
    else {
        return "false";
    }
}
 
// Driver Code
// Test Case 1:
let str1 = "9136812895@ybl";
console.log(isValid_UPI_ID(str1));
 
// Test Case 2:
let str2 = "rahul.12chauhan1998-1@okicici";
console.log(isValid_UPI_ID(str2));
 
// Test Case 3:
let str3 = "BNZAA2318JM";
console.log(isValid_UPI_ID(str3));
 
// Test Case 4:
let str4 = "MH 05 S 9954";
console.log(isValid_UPI_ID(str4));
 
// Test Case 5:
let str5 = "ViratKohli101@paytm";
console.log(isValid_UPI_ID(str5));
 
// Test Case 6:
let str6 = "Akanksha  @ybl";
console.log(isValid_UPI_ID(str6));

Output

true
true
false
false
true
false

Time Complexity: O(N) for each testcase, where N is the length of the given string.
Auxiliary Space: O(1)

Validating UPI IDs using Regular Expressions

C++

Java

Python3

C#

Javascript

Contact Us