C++ program to print prime numbers in a range using class

Given a range, we have to print all prime numbers in that range using the class and object approach.
Submitted by Shubh Pachori, on August 14, 2022

Example:

Input: 
Enter Range: 11 34

Output: 
Prime Numbers in the range 11 to 34 are 
11 13 17 19 23 29 31

C++ code to print prime numbers in a range using class and object approach

#include <iostream>
using namespace std;

// create a class
class IsPrime {
  // declare private data members
 private:
  int start, end;

  // public functions
 public:
  // getRange() function to insert range
  void getRange() {
    cout << "Enter Range:";
    cin >> start >> end;
  }

  // isPrime() function to print prime numbers in between range
  void isPrime() {
    // initilaize two int type variable for indexing
    int index_1, index_2;

    cout << "Prime Numbers in the range " << start << " to " << end << " are " << endl;

    // for loop to search prime number in the range
    for (index_1 = start; index_1 <= end; index_1++) {
      // counter variable
      int check = 0;

      // for loop for checking if the number is prime or not
      for (index_2 = 2; index_2 < index_1; index_2++) {
        // if condition to check if the index_1 is divisible by the index_2
        if (index_1 % index_2 == 0) {
          // counter increased by 1
          check++;

          // break statement to break the loop
          break;
        }
      }

      // if the counter is zero then the index_1 number is printed
      if (check == 0) {
        cout << index_1 << " ";
      }
    }
  }
};

int main() {
  // create a object
  IsPrime P;

  // calling getRange() function to insert range
  P.getRange();

  // IsPrime() function search prime numbers in the range
  P.isPrime();

  return 0;
}

Output:

Enter Range:9 25
Prime Numbers in the range 9 to 25 are 
11 13 17 19 23

Explanation:

In the above code, we have created a class IsPrime, two int-type data members start and end to store the start and end of the range, and public member functions getRange() and isPrime() to store and print prime numbers in between that given range.

In the main() function, we are creating an object P of class IsPrime, reading a range by the user using getRange() function, and finally calling the isPrime() member function to print the prime numbers in the given range. The isPrime() function contains the logic to print prime numbers in the given range and printing the result.