Validating Indian vehicle number plate using Regular Expression

Given a string str, the task is to validate if this string represents an Indian vehicle number.

A Number Plate consists of three parts :    

Where,

UP: First two Characters denote the State Name. Basically, Initial Characters of a State is used i.e. If the vehicle is from Uttar Pradesh then, 
UP Will denote the State Name.

50:Next Two Numbers indicate District's Sequential Number.

BY 1998:Next 6 (it varies from 5 to 6) letters are Unique alphanumeric string for each vehicle.

Examples:

Input: str = ”MH 05 S 9954?
Output: True
Explanation: MH – State Name 
05 – District Sequential Number
S 9954 – Alphanumeric Unique Code

Input: str = ”MH 05 DL 9023 ”
Output: True

Input: str = ”123@3459?
Output: False
Explanation: It has a unique character that is against the property of the Vehicle Number Plate code.

Input: str =”9345268?
Output: False
Explanation: As Contains Number Only

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

This problem can be dealt with regular expression. Regex will validate the entered data and will provide the exact format:

Create a regex pattern to validate the number as written below:   
regex="^[A-Z]{2}[\\ -]{0, 1}[0-9]{2}[\\ -]{0, 1}[A-Z]{1, 2}[\\ -]{0, 1}[0-9]{4}$" where

^: Beginning of the String
[A-Z]: Character Set, matches a character in the range "A" to "Z"
{2}: Quantifier, Match of the two preceding items
[\\ -]{0, 1} : Matches  one preceding item, It can be either space(\\) or Hyphen(-)
[0-9]{2}: Matches two preceding items, Both the item should be in the range 0 to 9
[A-Z]{1, 2}: It will match between  1 to 2, Item should be in the range "A"  to "Z" 
$: end of the String

Follow the steps mentioned below to implement the idea:

• Create a regex as shown above.
• Match the input string with the regex pattern.
• If the string matches the pattern then it is a valid number. Otherwise, it is not a valid number.

Below is the Code implementation of the above approach: 

// C++ program to validate
// Indian Vehicle Number Plate  using Regular Expression

#include <bits/stdc++.h>
#include <regex>
using namespace std;

// Function to validate the
// Indian Vehicle Number Plate
string isValidVehicleNumberPlate(string NUMBERPLATE)
{
    // Regex to check valid
    // Indian Vehicle Number Plate
    const regex pattern(
        "^[A-Z]{2}[\\ -]{0,1}[0-9]{2}[\\ "
        "-]{0,1}[A-Z]{1,2}[\\ -]{0,1}[0-9]{4}$");

    // Indian Vehicle Number Plate
    // is empty return false
    if (NUMBERPLATE.empty()) {
        return "false";
    }

    // Return true if the NUMBERPLATE
    // matched the ReGex
    if (regex_match(NUMBERPLATE, pattern)) {
        return "true";
    }
    else {
        return "false";
    }
}

// Driver Code
int main()
{
    // Test Case 1:
    string str1 = "UP 50 BY 1998";
    cout << isValidVehicleNumberPlate(str1) << endl;

    // Test Case 2:
    string str2 = "MH-05-DL-9023";
    cout << isValidVehicleNumberPlate(str2) << endl;

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

    // Test Case 4:
    string str4 = "MH 05 S 9954";
    cout << isValidVehicleNumberPlate(str4) << endl;

    // Test Case 5:
    string str5 = "934517865";
    cout << isValidVehicleNumberPlate(str5) << endl;

    // Test Case 6:
    string str6 = "MH05DL9023";
    cout << isValidVehicleNumberPlate(str6) << endl;

    return 0;
}

// This code is contributed by Aman Kumar.

// Java program to validate
// Indian Vehicle Number Plate  using Regular Expression

import java.util.regex.*;

class GFG {

    // Function to validate the
    // Indian Vehicle Number Plate (For India Country Only)
    public static boolean
    isValidVehicleNumberPlate(String NUMBERPLATE)
    {

        // Regex to check valid Indian Vehicle Number Plate
        String regex
            = "^[A-Z]{2}[\\ -]{0,1}[0-9]{2}[\\ -]{0,1}[A-Z]{1,2}[\\ -]{0,1}[0-9]{4}$";
        // Compile the ReGex
        Pattern p = Pattern.compile(regex);

        // If the  Indian Vehicle Number Plate
        // is empty return false
        if (NUMBERPLATE == null) {
            return false;
        }

        // Pattern class contains matcher() method
        // to find matching between given
        // Indian Vehicle Number Plate Validation  using
        // regular expression.
        Matcher m = p.matcher(NUMBERPLATE);

        // Return if the  Indian Vehicle Number Plate
        // matched the ReGex
        return m.matches();
    }

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

        // Test Case 1:
        String str1 = "UP 50 BY 1998";
        System.out.println(isValidVehicleNumberPlate(str1));

        // Test Case 2:
        String str2 = "MH-05-DL-9023";
        System.out.println(isValidVehicleNumberPlate(str2));

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

        // Test Case 4:
        String str4 = "MH 05 S 9954";
        System.out.println(isValidVehicleNumberPlate(str4));

        // Test Case 5:
        String str5 = "934517865";
        System.out.println(isValidVehicleNumberPlate(str5));

        // Test Case 6:
        String str6 = "MH05DL9023";
        System.out.println(isValidVehicleNumberPlate(str6));
    }
}

# Python3 program to validate
#  Indian Vehicle Number Plate using Regular Expression
import re

# Function to validate
# Indian Vehicle Number Plate
def isValidVehicleNumberPlate(str):

    # Regex to check valid Indian Vehicle Number Plate
    regex = "^[A-Z]{2}[\\s-]{0,1}[0-9]{2}[\\s-]{0,1}[A-Z]{1,2}[\\s-]{0,1}[0-9]{4}$"
    
    # 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

# Test Case 1:
str1 = "UP 50 BY 1998"
print(isValidVehicleNumberPlate(str1))

# Test Case 2:
str2 = "MH-05-DL-9023"
print(isValidVehicleNumberPlate(str2))

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

# Test Case 4:
str4 = "MH 05 S 9954"
print(isValidVehicleNumberPlate(str4))

# Test Case 5:
str5 = "934517865"
print(isValidVehicleNumberPlate(str5))

# Test Case 6:
str6 = "MH05DL9023"
print(isValidVehicleNumberPlate(str6))

// C# program to validate
// Indian Vehicle Number Plate using Regular Expression

using System;
using System.Text.RegularExpressions;

class GFG {

    // Function to validate the
    // Indian Vehicle Number Plate (For India Country Only)
    public static bool
    isValidVehicleNumberPlate(String NUMBERPLATE)
    {

        // Regex to check valid Indian Vehicle Number Plate
        string regex
            = "^[A-Z]{2}[\\ -]{0,1}[0-9]{2}[\\ -]{0,1}[A-Z]{1,2}[\\ -]{0,1}[0-9]{4}$";
        // Compile the ReGex
        Regex p = new Regex(regex);

        // If the Indian Vehicle Number Plate
        // is empty return false
        if (NUMBERPLATE == null) {
            return false;
        }

        // Pattern class contains matcher() method
        // to find matching between given
        // Indian Vehicle Number Plate Validation using
        // regular expression.
        Match m = p.Match(NUMBERPLATE);

        // Return if the Indian Vehicle Number Plate
        // matched the ReGex
        return m.Success;
    }

    // Driver Code.
    public static void Main()
    {

        // Test Case 1:
        string str1 = "UP 50 BY 1998";
        Console.WriteLine(isValidVehicleNumberPlate(str1));

        // Test Case 2:
        string str2 = "MH-05-DL-9023";
        Console.WriteLine(isValidVehicleNumberPlate(str2));

        // Test Case 3:
        string str3 = "BNZAA2318JM";
        Console.WriteLine(isValidVehicleNumberPlate(str3));

        // Test Case 4:
        string str4 = "MH 05 S 9954";
        Console.WriteLine(isValidVehicleNumberPlate(str4));

        // Test Case 5:
        string str5 = "934517865";
        Console.WriteLine(isValidVehicleNumberPlate(str5));

        // Test Case 6:
        string str6 = "MH05DL9023";
        Console.WriteLine(isValidVehicleNumberPlate(str6));
    }
}


// This code is contributed by Vaibhav nandan

// Javascript program to validate
// Indian Vehicle Number Plate  using Regular Expression

// Function to validate the
// Indian Vehicle Number Plate
function isValidVehicleNumberPlate(NUMBERPLATE) {
    // Regex to check valid
    // Indian Vehicle Number Plate
    let regex = new RegExp(/^[A-Z]{2}[ -][0-9]{1,2}(?: [A-Z])?(?: [A-Z]*)? [0-9]{4}$/);

    // Indian Vehicle Number Plate
    // is empty return false
    if (NUMBERPLATE == null) {
        return "false";
    }

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

// Driver Code
// Test Case 1:
let str1 = "UP 50 BY 1998";
console.log(isValidVehicleNumberPlate(str1));

// Test Case 2:
let str2 = "MH 05 DL 9023";
console.log(isValidVehicleNumberPlate(str2));

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

// Test Case 4:
let str4 = "MH 05 S 9954";
console.log(isValidVehicleNumberPlate(str4));

// Test Case 5:
let str5 = "934517865";
console.log(isValidVehicleNumberPlate(str5));

// Test Case 6:
let str6 = "MH 05 DL 9023";
console.log(isValidVehicleNumberPlate(str6));

// This code is contributed by akashish__

true
true
false
true
false
true

Time Complexity: O(N) where N is the length of the string
Auxiliary Space: O(1)