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How to validate CVV number using Regular Expression

  • Last Updated : 11 Nov, 2021

Given string str, the task is to check whether it is a valid CVV (Card Verification Value) number or not by using Regular Expression
The valid CVV (Card Verification Value) number must satisfy the following conditions: 

  1. It should have 3 or 4 digits.
  2. It should have a digit between 0-9.
  3. It should not have any alphabets and special characters.

Examples: 

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Input: str = “561” 
Output: true 
Explanation: 
The given string satisfies all the above mentioned conditions. Therefore, it is a valid CVV (Card Verification Value) number.



Input: str = “50614” 
Output: false 
Explanation: 
The given string has five-digit. Therefore, it is not a valid CVV (Card Verification Value) number.

Input: str = “5a#1” 
Output: false 
Explanation: The given string has alphabets and special characters. Therefore, it is not a valid CVV (Card Verification Value) number. 

Approach: The idea is to use Regular Expression to solve this problem. The following steps can be followed to compute the answer. 

  • Get the String.
  • Create a regular expression to check valid CVV (Card Verification Value) number as mentioned below:
regex = "^[0-9]{3, 4}$";
  • Where: 
    • ^ represents the starting of the string.
    • [0-9] represents the digit between 0-9.
    • {3, 4} represents the string has 3 or 4 digits.
    • $ represents the ending of the string.
  • Match the given string with the regular expression. In Java, this can be done by using Pattern.matcher().
  • Return true if the string matches with the given regular expression, else return false.

Below is the implementation of the above approach:

Java




// Java program to validate
// CVV (Card Verification Value)
// number using regex.
import java.util.regex.*;
class GFG {
 
    // Function to validate
    // CVV (Card Verification Value) number.
    // using regular expression.
    public static boolean isValidCVVNumber(String str)
    {
        // Regex to check valid CVV number.
        String regex = "^[0-9]{3,4}$";
 
        // Compile the ReGex
        Pattern p = Pattern.compile(regex);
 
        // If the string is empty
        // return false
        if (str == null)
        {
            return false;
        }
 
        // Find match between given string
        // and regular expression
        // using Pattern.matcher()
 
        Matcher m = p.matcher(str);
 
        // Return if the string
        // matched the ReGex
        return m.matches();
    }
 
    // Driver code
    public static void main(String args[])
    {
 
        // Test Case 1:
        String str1 = "561";
        System.out.println(isValidCVVNumber(str1));
 
        // Test Case 2:
        String str2 = "5061";
        System.out.println(isValidCVVNumber(str2));
 
        // Test Case 3:
        String str3 = "50614";
        System.out.println(isValidCVVNumber(str3));
 
        // Test Case 4:
        String str4 = "5a#1";
        System.out.println(isValidCVVNumber(str4));
    }
}

Python3




# Python3 program to validate
# CVV (Card Verification Value)
# number using regex.
import re
 
# Function to validate
# CVV (Card Verification Value) number.
# using regular expression.
 
 
def isValidCVVNumber(str):
 
    # Regex to check valid
    # CVV number.
    regex = "^[0-9]{3,4}$"
 
    # 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 = "561"
print(isValidCVVNumber(str1))
 
# Test Case 2:
str2 = "5061"
print(isValidCVVNumber(str2))
 
# Test Case 3:
str3 = "50614"
print(isValidCVVNumber(str3))
 
# Test Case 4:
str4 = "5a#1"
print(isValidCVVNumber(str4))
 
# This code is contributed by avanitrachhadiya2155

C++




// C++ program to validate the
// CVV (Card Verification Value) number
// using Regular Expression
#include <iostream>
#include <regex>
using namespace std;
 
// Function to validate the CVV
// (Card Verification Value) number
bool isValidCVVNumber(string str)
{
 
    // Regex to check valid CVV
    // (Card Verification Value) number
    const regex pattern("^[0-9]{3,4}$");
 
    // If the CVV (Card Verification Value)
    //  number is empty return false
    if (str.empty())
    {
        return false;
    }
 
    // Return true if the CVV
    // (Card Verification Value) number
    // matched the ReGex
    if (regex_match(str, pattern))
    {
        return true;
    }
    else
    {
        return false;
    }
}
 
// Driver Code
int main()
{
    // Test Case 1:
    string str1 = "561";
    cout << isValidCVVNumber(str1) << endl;
 
    // Test Case 2:
    string str2 = "5061";
    cout << isValidCVVNumber(str2) << endl;
 
    // Test Case 3:
    string str3 = "50614";
    cout << isValidCVVNumber(str3) << endl;
 
    // Test Case 4:
    string str4 = "5a#1";
    cout << isValidCVVNumber(str4) << endl;
 
    return 0;
}
 
// This code is contributed by yuvraj_chandra
Output
true
true
false
false



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