How to validate PAN Card number using Regular Expression

Given string str of alphanumeric characters, the task is to check whether the string is a valid PAN (Permanent Account Number) Card number or not by using Regular Expression.
The valid PAN Card number must satisfy the following conditions: 

1. It should be ten characters long.
2. The first five characters should be any upper case alphabets.
3. The next four-characters should be any number from 0 to 9.
4. The last(tenth) character should be any upper case alphabet.
5. It should not contain any white spaces.

Examples:

Input: str = "BNZAA2318J" 
Output: true 
Explanation: 
The given string satisfies all the above mentioned conditions.

Input: str = "23ZAABN18J" 
Output: false 
Explanation: 
The given string not starts with upper case alphabets, therefore it is not a valid PAN Card number.

Input: str = "BNZAA2318JM" 
Output: false 
Explanation: 
The given string contains eleven characters, therefore it is not a valid PAN Card number.

Input: str = "BNZAA23184" 
Output: true 
Explanation: 
The last(tenth) character of this string is a numeric(0-9) character, therefore it is not a valid PAN Card number. 

Input: str = "BNZAA 23184" 
Output: true 
Explanation: 
The given string contains white spaces, therefore it is not a valid PAN Card number. 

Approach: This problem can be solved by using Regular Expression. 

• Get the string.
• Create a regular expression to validate the PAN Card number as mentioned below:

regex = "[A-Z]{5}[0-9]{4}[A-Z]{1}";

• Where: 
  
  • [A-Z]{5} represents the first five upper case alphabets which can be A to Z.
  • [0-9]{4} represents the four numbers which can be 0-9.
  • [A-Z]{1} represents the one upper case alphabet which can be A to Z.
• Match the given string with the regex, in Java, this can be done using Pattern.matcher().
• Return true if the string matches with the given regex, else return false.

Below is the implementation of the above approach: 

// C++ program to validate the
// PAN Card number using Regular 
//  Expression

#include <iostream>
#include <regex>
using namespace std;

// Function to validate the 
// PAN Card number.
bool isValidPanCardNo(string panCardNo)
{

    // Regex to check valid 
    // PAN Card number.
    const regex pattern("[A-Z]{5}[0-9]{4}[A-Z]{1}");

    // If the PAN Card number
    // is empty return false
    if (panCardNo.empty()) {
        return false;
    }

    // Return true if the PAN Card number
    // matched the ReGex
    if (regex_match(panCardNo, pattern)) 
    {
        return true;
    }
    else 
    {
        return false;
    }
}

// Driver Code
int main()
{
    // Test Case 1:
    string str1 = "BNZAA2318J";
    cout << isValidPanCardNo(str1) << endl;

    // Test Case 2:
    string str2 = "23ZAABN18J";
    cout << isValidPanCardNo(str2) << endl;

    // Test Case 3:
    string str3 = "BNZAA2318JM";
    cout << isValidPanCardNo(str3) << endl;

    // Test Case 4:
    string str4 = "BNZAA23184";
    cout << isValidPanCardNo(str4) << endl;

    // Test Case 5:
    string str5 = "BNZAA 23184";
    cout << isValidPanCardNo(str5) << endl;

    return 0;
}

// This code is contributed by yuvraj_chandra

// Java program to validate the
// PAN Card number using Regular Expression

import java.util.regex.*;

class GFG
{

    // Function to validate the PAN Card number.
    public static boolean isValidPanCardNo(String panCardNo)
    {

        // Regex to check valid PAN Card number.
        String regex = "[A-Z]{5}[0-9]{4}[A-Z]{1}";

        // Compile the ReGex
        Pattern p = Pattern.compile(regex);

        // If the PAN Card number
        // is empty return false
        if (panCardNo == null) 
        {
            return false;
        }

        // Pattern class contains matcher() method
        // to find matching between given
        // PAN Card number using regular expression.
        Matcher m = p.matcher(panCardNo);

        // Return if the PAN Card number
        // matched the ReGex
        return m.matches();
    }

    // Driver Code.
    public static void main(String args[])
    {

        // Test Case 1:
        String str1 = "BNZAA2318J";
        System.out.println(isValidPanCardNo(str1));

        // Test Case 2:
        String str2 = "23ZAABN18J";
        System.out.println(isValidPanCardNo(str2));

        // Test Case 3:
        String str3 = "BNZAA2318JM";
        System.out.println(isValidPanCardNo(str3));

        // Test Case 4:
        String str4 = "BNZAA23184";
        System.out.println(isValidPanCardNo(str4));

        // Test Case 5:
        String str5 = "BNZAA 23184";
        System.out.println(isValidPanCardNo(str5));
    }
}

# Python3 program to validate the
# PAN Card number using Regular
# Expression
import re

# Function to validate the
# PAN Card number.


def isValidPanCardNo(panCardNo):

    # Regex to check valid
    # PAN Card number
    regex = "[A-Z]{5}[0-9]{4}[A-Z]{1}"

    # Compile the ReGex
    p = re.compile(regex)

    # If the PAN Card number
    # is empty return false
    if(panCardNo == None):
        return False

    # Return if the PAN Card number
    # matched the ReGex
    if(re.search(p, panCardNo) and
       len(panCardNo) == 10):
        return True
    else:
        return False

# Driver Code.


# Test Case 1:
str1 = "BNZAA2318J"
print(isValidPanCardNo(str1))

# Test Case 2:
str2 = "23ZAABN18J"
print(isValidPanCardNo(str2))

# Test Case 3:
str3 = "BNZAA2318JM"
print(isValidPanCardNo(str3))

# Test Case 4:
str4 = "BNZAA23184"
print(isValidPanCardNo(str4))

# Test Case 5:
str5 = "BNZAA 23184"
print(isValidPanCardNo(str5))

# This code is contributed by avanitrachhadiya2155

// C# program to validate the
// PAN Card numbe
//using Regular Expressions
using System;
using System.Text.RegularExpressions;
class GFG
{

  // Main Method
  static void Main(string[] args)
  {

    // Input strings to Match
    // PAN Card numbe
    string[] str={"BNZAA2318J","23ZAABN18J","BNZAA2318JM","BNZAA23184","BNZAA 23184"};
    foreach(string s in str) {
      Console.WriteLine( isValidPanCardNo(s) ? "true" : "false");
    }
    Console.ReadKey(); }

  // method containing the regex
  public static bool isValidPanCardNo(string str)
  {
    string strRegex = @"[A-Z]{5}[0-9]{4}[A-Z]{1}$";
    Regex re = new Regex(strRegex);
    if (re.IsMatch(str))
      return (true);
    else
      return (false);
  }
}

// This code is contributed by Rahul Chauhan

// Javascript program to validate
// PAN Number  using Regular Expression

// Function to validate the
// PAN Number 
function isValidPanCardNo(panCardNo) {
    // Regex to check valid
    // PAN Number
    let regex = new RegExp(/^[A-Z]{5}[0-9]{4}[A-Z]{1}$/);

    // if PAN Number 
    // is empty return false
    if (panCardNo == null) {
        return "false";
    }

    // Return true if the PAN NUMBER
    // matched the ReGex
    if (regex.test(panCardNo) == true) {
        return "true";
    }
    else {
        return "false";
    }
}

// Driver Code
// Test Case 1:
let str1 = "BOSPC9911H";
console.log(isValidPanCardNo(str1));

// Test Case 2:
let str2 = "23ZAABN18J";
console.log(isValidPanCardNo(str2));

// Test Case 3:
let str3 = "BNZAA2318JM";
console.log(isValidPanCardNo(str3));

// Test Case 4:
let str4 = "BNZAA23184";
console.log(isValidPanCardNo(str4));

// Test Case 5:
let str5 = "BNZAA 23184";
console.log(isValidPanCardNo(str5));

// This code is contributed by Rahul Chauhan

true
false
false
false
false

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