Example: Finding and Extracting Substrings

// Finding and Extracting Substrings
#include <iostream>
#include <string>
using namespace std;

int main() {
    // Step 1: Declare a source string
    string sentence = "The quick brown fox jumps over the lazy dog.";

    // Step 2: Find the position of a substring
    string searchWord = "fox";
    size_t foundPos = sentence.find(searchWord); // size_t is an unsigned type

    if (foundPos != string::npos) { // string::npos indicates not found
        cout << "'" << searchWord << "' found at position: " << foundPos << endl;

        // Step 3: Extract a substring starting from the found position
        // Syntax: substr(start_index, length)
        string extractedWord = sentence.substr(foundPos, searchWord.length());
        cout << "Extracted word: " << extractedWord << endl;

        // Step 4: Extract a substring from a specific point to the end
        string restOfString = sentence.substr(foundPos);
        cout << "Rest of the string from 'fox': " << restOfString << endl;

        // Step 5: Extract a specific range (e.g., "quick brown")
        size_t startQ = sentence.find("quick");
        string quickBrown = sentence.substr(startQ, 11); // "quick brown" has 11 chars
        cout << "Extracted 'quick brown': " << quickBrown << endl;

    } else {
        cout << "'" << searchWord << "' not found." << endl;
    }

    return 0;
}