Program to find all match of a regex in a string

Prerequisite: smatch | Regex (Regular Expressions) in C++ Given a regex, the task is to find all regex matches in a string.

Without using iterator:

Implementation:

CPP

// C++ program to find all the matches
#include <bits/stdc++.h>
using namespace std;
int main()
{
    string subject("My GeeksforGeeks is my "
                    "GeeksforGeeks none of your GeeksforGeeks");

    // Template instantiations for
    // extracting the matching pattern.
    smatch match;
    regex r("GeeksforGeeks");
    int i = 1;
    while (regex_search(subject, match, r)) {
        cout << "\nMatched string is " << match.str(0) << endl
            << "and it is found at position "
            << match.position(0)<<endl;
        i++;

        // suffix to find the rest of the string.
        subject = match.suffix().str();
    }
    return 0;
}

Java

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
  public static void main(String[] args) {
    String subject = "My GeeksforGeeks is my GeeksforGeeks none of your GeeksforGeeks";
    Pattern pattern = Pattern.compile("GeeksforGeeks");
    Matcher matcher = pattern.matcher(subject);
    int i = 1;

    while (matcher.find()) {
      System.out.println("\nMatched string is " + matcher.group(0));
      System.out.println("and it is found at position " + matcher.start());
      i++;

      // suffix to find the rest of the string.
      subject = subject.substring(matcher.end());
      matcher = pattern.matcher(subject);
    }
  }
}

Python3

# Python program to find all the matches
import re

subject = "My GeeksforGeeks is my GeeksforGeeks none of your GeeksforGeeks"

# Template instantiations for
# extracting the matching pattern.
match = re.search("GeeksforGeeks", subject)
i = 1

while match:
    print("\nMatched string is", match.group(0))
    print("and it is found at position", match.start())
    i += 1

    # suffix to find the rest of the string.
    subject = subject[(match.end()):]
    match = re.search("GeeksforGeeks", subject)

using System;
using System.Text.RegularExpressions;

class Program
{
    static void Main(string[] args)
    {
        string subject = "My GeeksforGeeks is my GeeksforGeeks none of your GeeksforGeeks";
        
       // Template instantiations for
       // extracting the matching pattern.
        Regex r = new Regex("GeeksforGeeks");
        Match match;
        int i = 1;
        while ((match = r.Match(subject)).Success)
        {
            Console.WriteLine("\nMatched string is " + match.Value
                                + "\nand it is found at position " + match.Index);
            i++;

            // suffix to find the rest of the string.
            subject = subject.Substring(match.Index + match.Length);
        }
    }
}

JavaScript

// JavaScript program to find all the matches
let subject = "My GeeksforGeeks is my GeeksforGeeks none of your GeeksforGeeks";
let match = subject.match("GeeksforGeeks");
let i = 1;

// loop to find the rest of the string
while (match) {
    console.log("\nMatched string is", match[0]);
    console.log("and it is found at position", match.index);
    i += 1;

    // suffix to find the rest of the string
    subject = subject.substring(match.index + match[0].length);
    match = subject.match("GeeksforGeeks");
}

Output

Matched string is GeeksforGeeks
and it is found at position 3

Matched string is GeeksforGeeks
and it is found at position 7

Matched string is GeeksforGeeks
and it is found at position 14

Note: Above code is running perfectly fine but the problem is input string will be lost.
Using iterator: Object can be constructed by calling the constructor with three parameters: a string iterator indicating the starting position of the search, a string iterator indicating the ending position of the search, and the regex object. Construct another iterator object using the default constructor to get an end-of-sequence iterator.