How to check Aadhaar number is valid or not using Regular Expression - GeeksforGeeks

31 Mar, 2022
Given string str, the task is to check whether the given string is a valid Aadhaar number or not by using Regular Expression. The valid Aadhaar number must satisfy the following conditions: 
It should have 12 digits.It should not start with 0 and 1.It should not contain any alphabet and special characters.It should have white space after every 4 digits.
It should have 12 digits.
It should not start with 0 and 1.
It should not contain any alphabet and special characters.
It should have white space after every 4 digits.
Examples: 
Input: str = “3675 9834 6012” Output: true Explanation: The given string satisfies all the above mentioned conditions. Therefore, it is a valid Aadhaar number.Input: str = “3675 9834 6012 8” Output: false Explanation: The given string contains 13 digits. Therefore, it is not a valid Aadhaar 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 Aadhaar number as mentioned below:
regex = “^[2-9]{1}[0-9]{3}\\s[0-9]{4}\\s[0-9]{4}$”;
Where: ^ represents the starting of the string.[2-9]{1} represents the first digit should be any from 2-9.[0-9]{3} represents the next 3 digits after the first digit should be any digit from 0-9.\\s represents white space.[0-9]{4} represents the next 4 digits should be any from 0-9.\\s represents white space.[0-9]{4} represents the next 4 digits should be any from 0-9.$ represents the ending of the string.
^ represents the starting of the string.
[2-9]{1} represents the first digit should be any from 2-9.
[0-9]{3} represents the next 3 digits after the first digit should be any digit from 0-9.
\\s represents white space.
[0-9]{4} represents the next 4 digits should be any from 0-9.
\\s represents white space.
[0-9]{4} represents the next 4 digits should be any from 0-9.
$ 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: 
C++
Java
Python3
// C++ program to validate the// Aadhaar number using Regular Expression#include <iostream>#include <regex>using namespace std; // Function to validate the Aadhaar number.bool isValidAadhaarNumber(string str){   // Regex to check valid Aadhaar number.  const regex pattern("^[2-9]{1}[0-9]{3}\\s[0-9]{4}\\s[0-9]{4}$");   // If the Aadhaar number  // is empty return false  if (str.empty())  {     return false;  }   // Return true if the Aadhaar number  // matched the ReGex  if(regex_match(str, pattern))  {    return true;  }  else  {    return false;  }} // Driver Codeint main(){  // Test Case 1:  string str1 = "3675 9834 6015";  cout << isValidAadhaarNumber(str1) << endl;   // Test Case 2:  string str2 = "4675 9834 6012 8";  cout << isValidAadhaarNumber(str2) << endl;   // Test Case 3:  string str3 = "0175 9834 6012";  cout << isValidAadhaarNumber(str3) << endl;   // Test Case 4:  string str4 = "3675 98AF 60#2";  cout << isValidAadhaarNumber(str4) << endl;   // Test Case 5:  string str5 = "417598346012";  cout << isValidAadhaarNumber(str5) << endl;  return 0;} // This code is contributed by yuvraj_chandra
// Java program to check valid// Aadhaar number using regex. import java.util.regex.*;class GFG {     // Function to validate Aadhaar number.    public static boolean    isValidAadhaarNumber(String str)    {        // Regex to check valid Aadhaar number.        String regex            = "^[2-9]{1}[0-9]{3}\\s[0-9]{4}\\s[0-9]{4}$";         // Compile the ReGex        Pattern p = Pattern.compile(regex);         // If the string is empty        // return false        if (str == null) {            return false;        }         // Pattern class contains matcher() method        // to find matching between given string        // and regular expression.        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 = "3675 9834 6015";        System.out.println(isValidAadhaarNumber(str1));         // Test Case 2:        String str2 = "4675 9834 6012 8";        System.out.println(isValidAadhaarNumber(str2));         // Test Case 3:        String str3 = "0175 9834 6012";        System.out.println(isValidAadhaarNumber(str3));         // Test Case 4:        String str4 = "3675 98AF 60#2";        System.out.println(isValidAadhaarNumber(str4));         // Test Case 5:        String str5 = "417598346012";        System.out.println(isValidAadhaarNumber(str5));    }}
# Python3 program to validate# Aadhaar number using regex.import re # Function to validate Aadhaar# number.def isValidAadhaarNumber(str):     # Regex to check valid    # Aadhaar number.    regex = ("^[2-9]{1}[0-9]{3}\\" +             "s[0-9]{4}\\s[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 = "3675 9834 6015"print(isValidAadhaarNumber(str1)) # Test Case 2:str2 = "4675 9834 6012 8"print(isValidAadhaarNumber(str2)) # Test Case 3:str3 = "0175 9834 6012"print(isValidAadhaarNumber(str3)) # Test Case 4:str4 = "3675 98AF 60#2"print(isValidAadhaarNumber(str4)) # Test Case 5:str5 = "417598346012"print(isValidAadhaarNumber(str5)) # This code is contributed by avanitrachhadiya2155
true
false
false
false
false
 
avanitrachhadiya2155
yuvraj_chandra
rkbhola5
CPP-regex
java-regular-expression
Pattern Searching
Strings
Strings
Pattern Searching
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