Regular Expressions to Validate Account Office Reference Number

Given some Account Office Reference Number, the task is to check if they are valid or not using regular expressions. Rules for the valid  Account Office Reference Number are:

• It is an alphanumeric string containing upper-case letters and digits.
• Accounts Office Reference Number is a unique, 13-character code.
• It starts with digits (0-9) and ends with digits.
• Its first three places are reserved for digits.
• After the first three characters, two places are occupied by uppercase alphabet letters (A-Z).
• After the first five characters, the next 8 places are reserved for digits (0-9).

Examples:

Input: str = ”123IN12345678.″
Output: True

Input: str = ”IN12345678901″
Output: False
Explanation: As it starts with an alphabet letter.

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

Create a regex pattern to validate the number as written below:   
regex = “^[0-9]{3}[A-Z]{2}[0-9]{8}$“

Where,

• ^ : Start of the string
• [0-9]{3}: This pattern will match 3 of the preceding items if they are digits(0-9)
• [A-Z]{2}: This pattern will match two of the preceding items if they are Uppercase Alphabet letters
• [0-9]{8}: This pattern will allow 8 of the preceding tokens if they are digits
• $: End of the string

Follow the below steps to implement the idea:

• Create a regex expression for Account Office Reference Number
• Use Pattern class to compile the regex formed.
• Use the matcher function to check whether the Account Office Reference Number is valid or not.
• If it is valid, return true. Otherwise, return false.

Below is the code implementation of the above-discussed approach:

Java

// Java program to validate the
// Account Office Reference Number
// using Regular Expression

import java.util.regex.*;

class GFG {

    // Function to validate the
    // Account Office Reference Number
    public static boolean
    isValid_AccOffcRefNumber(String str)
    {

        // Regex to check valid
        // Account Office Reference Number
        String regex = "^[0-9]{3}[A-Z]{2}[0-9]{8}$";

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

        // If the str
        // is empty return false
        if (str == null) {
            return false;
        }

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

        // Return if the str
        // matched the ReGex
        return m.matches();
    }

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

        // Test Case 1:
        String str1 = "123IN12345678";
        System.out.println(isValid_AccOffcRefNumber(str1));

        // Test Case 2:
        String str2 = "123AZ12345678";
        System.out.println(isValid_AccOffcRefNumber(str2));

        // Test Case 3:
        String str3 = "123456AB78901";
        System.out.println(isValid_AccOffcRefNumber(str3));

        // Test Case 4:
        String str4 = "AA123456789AB";
        System.out.println(isValid_AccOffcRefNumber(str4));

        // Test Case 5:
        String str5 = "AA12345678012";
        System.out.println(isValid_AccOffcRefNumber(str5));
    }
}

C++

// C++ program to validate the
// Account Office Reference Numbers
// using Regular Expression

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

// Function to validate the
// Account Office Reference Number
bool isValid_AccOffcRefNumber(string str)
{

    // Regex to check valid
    // Account Office Reference Number
    const regex pattern("^[0-9]{3}[A-Z]{2}[0-9]{8}$");

    // If the str
    // is empty return false
    if (str.empty()) {
        return false;
    }

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

// Driver Code
int main()
{
    // Test Case 1:
    string str1 = "123IN12345678";
    cout << isValid_AccOffcRefNumber(str1) << endl;

    // Test Case 2:
    string str2 = "123AZ12345678";
    cout << isValid_AccOffcRefNumber(str2) << endl;

    // Test Case 3:
    string str3 = "123456AB78901";
    cout << isValid_AccOffcRefNumber(str3) << endl;

    // Test Case 4:
    string str4 = "AA123456789AB";
    cout << isValid_AccOffcRefNumber(str4) << endl;

    // Test Case 5:
    string str5 = "AA12345678012";
    cout << isValid_AccOffcRefNumber(str5) << endl;

    return 0;
}

Python3

# Python3 program to validate
# Account Office Reference Number using
# Regular Expression
import re

# Function to validate
# Account Office Reference Number


def isValid_AccOffcRefNumber(str):

    # Regex to check valid
    # Account Office Reference Number
    regex = "^[0-9]{3}[A-Z]{2}[0-9]{8}$"

    # 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 = "123IN12345678"
print(isValid_AccOffcRefNumber(str1))

# Test Case 2:
str2 = "123AZ12345678"
print(isValid_AccOffcRefNumber(str2))

# Test Case 3:
str3 = "123456AB78901"
print(isValid_AccOffcRefNumber(str3))

# Test Case 4:
str4 = "AA123456789AB"
print(isValid_AccOffcRefNumber(str4))

# Test Case 5:
str5 = "AA12345678012"
print(isValid_AccOffcRefNumber(str5))

C#

// C# program to validate the
// Account Office Reference Number
// using Regular Expressions
using System;
using System.Text.RegularExpressions;
class GFG {

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

        // Input strings to Match
        // Account Office Reference Number
        string[] str = { "123IN12345678", "123AZ12345678",
                         "123456AB78901", "AA123456789AB",
                         "AA12345678012" };
        foreach(string s in str)
        {
            Console.WriteLine(isValid_AccOffcRefNumber(s)
                                  ? "true"
                                  : "false");
        }
        Console.ReadKey();
    }

    // method containing the regex
    public static bool isValid_AccOffcRefNumber(string str)
    {
        string strRegex = @"^[0-9]{3}[A-Z]{2}[0-9]{8}$";
        Regex re = new Regex(strRegex);
        if (re.IsMatch(str))
            return (true);
        else
            return (false);
    }
}

PHP

<?php
// PHP program to validate Account Office Reference Number
// Function to validate Account Office Reference Number using regular expression
function isValid_AccOffcRefNumber($str){
if(preg_match('/^[0-9]{3}[A-Z]{2}[0-9]{8}$/', $str)) {
echo "true\n";
} else {
echo "false\n";
}
}
isValid_AccOffcRefNumber("123IN12345678");
isValid_AccOffcRefNumber("123AZ12345678");
isValid_AccOffcRefNumber("123456AB78901");
isValid_AccOffcRefNumber("AA123456789AB");
isValid_AccOffcRefNumber("AA12345678012");
?>

Javascript

// Javascript program to validate
// Account Office Reference Number
//using Regular Expression

// Function to validate the
// Account Office Reference Number
function isValid_AccOffcRefNumber(str) {
    // Regex to check valid
    // Account Office Reference Number
    let regex = new RegExp(/^[0-9]{3}[A-Z]{2}[0-9]{8}$/);

    // if str
    // is empty return false
    if (str == null) {
        return "false";
    }

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

// Driver Code
// Test Case 1:
let str1 = "123IN12345678";
console.log(isValid_AccOffcRefNumber(str1));

// Test Case 2:
let str2 = "123AZ12345678";
console.log(isValid_AccOffcRefNumber(str2));

// Test Case 3:
let str3 = "123456AB78901";
console.log(isValid_AccOffcRefNumber(str3));

// Test Case 4:
let str4 = "AA123456789AB";
console.log(isValid_AccOffcRefNumber(str4));

// Test Case 5:
let str5 = "AA12345678012";
console.log(isValid_AccOffcRefNumber(str5));

Output

true
true
false
false
false

Time complexity: O(n) // where n is the length of the string.

Auxiliary space: O(1)