How to validate IFSC Code using Regular Expression

25 May, 2021
Given string str, the task is to check whether the given string is a valid IFSC (Indian Financial System) Code or not by using Regular Expression. The valid IFSC (Indian Financial System) Code must satisfy the following conditions: 
It should be 11 characters long.The first four characters should be upper case alphabets.The fifth character should be 0.The last six characters usually numeric, but can also be alphabetic.
It should be 11 characters long.
The first four characters should be upper case alphabets.
The fifth character should be 0.
The last six characters usually numeric, but can also be alphabetic.
Examples: 
Input: str = “SBIN0125620”; Output: true Explanation: The given string satisfies all the above-mentioned conditions. Therefore, it is a valid IFSC (Indian Financial System) Code.Input: str = “SBIN0125”; Output: false Explanation: The given string has 8 characters. Therefore it is not a valid IFSC (Indian Financial System) Code.Input: str = “1234SBIN012”; Output: false Explanation: The given string doesn’t starts with alphabets. Therefore it is not a valid IFSC (Indian Financial System) Code.
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 IFSC (Indian Financial System) Code as mentioned below:
regex = "^[A-Z]{4}0[A-Z0-9]{6}$";
Where: ^ represents the starting of the string.[A-Z]{4} represents the first four characters should be upper case alphabets.0 represents the fifth character should be 0.[A-Z0-9]{6} represents the next six characters usually numeric, but can also be alphabetic.$ represents the ending of the string.
^ represents the starting of the string.
[A-Z]{4} represents the first four characters should be upper case alphabets.
0 represents the fifth character should be 0.
[A-Z0-9]{6} represents the next six characters usually numeric, but can also be alphabetic.
$ represents the ending of the string.
Below is the implementation of the above approach: 
C++
Java
Python3
// C++ program to validate the// IFSC (Indian Financial System) Code using Regular Expression#include <iostream>#include <regex>using namespace std; // Function to validate the IFSC (Indian Financial System) Code.bool isValidIFSCode(string str){   // Regex to check valid IFSC (Indian Financial System) Code.  const regex pattern("^[A-Z]{4}0[A-Z0-9]{6}$");    // If the IFSC (Indian Financial System) Code  // is empty return false  if (str.empty())  {     return false;  }   // Return true if the IFSC (Indian Financial System) Code  // matched the ReGex  if(regex_match(str, pattern))  {    return true;  }  else  {    return false;  }} // Driver Codeint main(){     // Test Case 1:  string str1 = "SBIN0125620";  cout << boolalpha << isValidIFSCode(str1) << endl;   // Test Case 2:  string str2 = "SBIN0125";  cout << boolalpha << isValidIFSCode(str2) << endl;   // Test Case 3:  string str3 = "1234SBIN012";  cout << boolalpha << isValidIFSCode(str3) << endl;   // Test Case 4:  string str4 = "SBIN7125620";  cout << boolalpha <<isValidIFSCode(str4) << endl;   return 0;} // This code is contributed by yuvraj_chandra
// Java program to validate// IFSC (Indian Financial System) Code// using regular expression.import java.util.regex.*;class GFG {     // Function to validate    // IFSC (Indian Financial System) Code    // using regular expression.    public static boolean isValidIFSCode(String str)    {        // Regex to check valid IFSC Code.        String regex = "^[A-Z]{4}0[A-Z0-9]{6}$";         // 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        // the given string and        // the 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 = "SBIN0125620";        System.out.println(isValidIFSCode(str1));         // Test Case 2:        String str2 = "SBIN0125";        System.out.println(isValidIFSCode(str2));         // Test Case 3:        String str3 = "1234SBIN012";        System.out.println(isValidIFSCode(str3));         // Test Case 4:        String str4 = "SBIN7125620";        System.out.println(isValidIFSCode(str4));    }}
# Python3 program to validate# IFSC (Indian Financial System) Code # using regular expressionimport re # Function to validate# IFSC (Indian Financial System) Code# using regular expression.def  isValidIFSCode(str):     # Regex to check valid IFSC Code.    regex = "^[A-Z]{4}0[A-Z0-9]{6}$"         # 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 = "SBIN0125620"print(isValidIFSCode(str1)) # Test Case 2:str2 = "SBIN0125"print(isValidIFSCode(str2)) # Test Case 3:str3 = "1234SBIN012"print(isValidIFSCode(str3)) # Test Case 4:str4 = "SBIN7125620"print(isValidIFSCode(str4)) # This code is contributed by avanitrachhadiya2155
true
false
false
false

Using String.matches() method
This method tells whether or not this string matches the given regular expression. An invocation of this method of the form str.matches(regex) yields exactly the same result as the expression Pattern.matches(regex, str). Pattern.compile(regex) compiles the pattern so that when you execute Matcher.matches(), the pattern is not recompiled again and again. Pattern.compile pre compiles it. However, if you use string.matches, it compiles the pattern every time you execute this line. So, it is better to use Pattern.compile().
Java
// Java program to validate// IFSC (Indian Financial System) Code// using regular expression.class GFG {     // Function to validate    // IFSC (Indian Financial System) Code    // using regular expression.    public static boolean isValidIFSCode(String str)    {        // Regex to check valid IFSC Code.        String regex = "^[A-Z]{4}0[A-Z0-9]{6}$";        return str.trim().matches(regex);    }     // Driver Code.    public static void main(String args[])    {         // Test Case 1:        String str1 = "SBIN0125620";        System.out.println(isValidIFSCode(str1));         // Test Case 2:        String str2 = "SBIN0125";        System.out.println(isValidIFSCode(str2));         // Test Case 3:        String str3 = "1234SBIN012";        System.out.println(isValidIFSCode(str3));         // Test Case 4:        String str4 = "SBIN7125620";        System.out.println(isValidIFSCode(str4));    }}
true
false
false
false

avanitrachhadiya2155
yuvraj_chandra
subho57
CPP-regex
java-regular-expression
regular-expression
Pattern Searching
Strings
Strings
Pattern Searching
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