C++ program to replace a word by another given word in the string using class

Given a string, we have to replace a word by another given word using the class and object approach.
Submitted by Shubh Pachori, on September 01, 2022

Example:

Input:
Enter String : his book is here.

Output: 
Enter String replace : his
Enter String to replace : her
Edited String : her book is here.

C++ code to replace a word by another given word in the string using the class and object approach

#include <iostream>
#include <string>

using namespace std;

// create a class
class String {
  // private data members
 private:
  string str;
  string strrep;
  string strtorep;

  // public members functions
 public:
  // getString() function to input string
  void getString() {
    cout << "Enter String : ";
    getline(cin, str);
  }

  // getSwap() function to input replace
  // word and by which replace
  void getSwap() {
    cout << "Enter String replace : ";
    cin >> strrep;

    cout << "Enter String to replace : ";
    cin >> strtorep;
  }

  // swapString() function to swap words
  string swapString() {
    // initializing int and string type variables to
    // perform operations and manipulations
    int index_1, index_2;
    string temp_1;
    string temp_2;

    // for loop for traversing the whole string
    for (index_1 = 0; str[index_1]; index_1++) {
      // copying words to temp_1 one by one of the string
      temp_1 = str.substr(index_1, strrep.length()), temp_2;

      // if replacing word is equal to the word in temp_1
      if (strrep == temp_1) {
        // the copy replacing word to temp_2
        temp_2 = strtorep;

        // for loop to swap words
        for (index_2 = 0; index_2 < strrep.length(); index_2++) {
          // append word in temp_2 to the string
          str[index_1 + index_2] = temp_2[index_2];
        }
      }
    }

    // transfering null
    str[index_1] = 0;

    // returning the edited string
    return str;
  }
};

int main() {
  // create an object
  String S;

  // string type variable to store edited string
  string str;

  // calling getString() function to insert the string
  S.getString();

  // getSwap() function to insert the replacing
  // and replaced words
  S.getSwap();

  // calling swapString() function to swap the
  // words in the string
  str = S.swapString();

  cout << "Edited String : " << str;

  return 0;
}

Output:

Enter String: sum of numbers
Enter String replace: sum
Enter String to replace: mul
Edited String : mul of numbers

Explanation:

In the above code, we have created a class String, three string type string data member str, strrep, and strtorep to store the string, word to replace and replacing word, and public member functions getString(), getSwap() and swapString()to store the string and word to replace and replacing word and to swap words in the string.

In the main() function, we are creating an object S of class String, reading the string using the getString() function, reading word to be replaced and replacing words using getSwap() function, and finally calling the swapString() member function to swap words in the string. The swapString() function contains the logic to swap words in the string and printing the result.