Simple Parameterized Constructor For Find Prime Number Example Program In C++

Definition

In C++, Constructor is automatically called when an object( the instance of the class) create.It is a special member function of the class.

• It has the same name of the class.
• It must be a public member.
• No Return Values.
• Default constructors are called when constructors are not defined for the classes.

Prime Number Calculation Algorithm/Steps:

• STEP 1:  Start the program.
• STEP 2:  Declare the class as Prime with data members and Member functions.
• STEP 3:  Consider the argument constructor Prime() with integer Argument.
• STEP 4:  To call the function calculate() and do the following steps.
• STEP 5:  For i=2 to a/2 do
• STEP 6:  Check if a%i==0 then set k=0 and break.
• STEP 7:  Else set k value as 1.
• STEP 8:  Increment the value i as 1.
• STEP 9:  Check whether the k value is 1 or 0.
• STEP 10: If it is 1 then display the value is a prime number.
• STEP 11: Else display the value is not prime.
• STEP 12: Stop the program.

Syntax

class class_name {
    Access Specifier :
    Member_Variables
    Member_Functions
public:
    class_name(variables) {
        // Constructor code 
    }

    //... other Variables & Functions
}

Example Program

/*  Simple Parameterized Constructor For Prime Number Example Program In C++ 
    Understanding Class and Constructors            */

#include<iostream>
#include<conio.h>

using namespace std;

// Prime Class Declaration
class Prime {
   //Member Variable Declaration
   int a, k, i;
public:
   // Parameterized Constructor definition
   Prime(int x) {
      a = x;

      k = 1;
      {
         for (i = 2; i <= a / 2; i++)
            if (a % i == 0) {
               k = 0;
               break;
            } else {
               k = 1;
            }
      }
   }
   
   //Member Function show() for display result.
   void show() {
      if (k == 1)
         cout << a << " is Prime Number.";
      else
         cout << a << " is Not Prime Numbers.";
   }
};

//Main Function
int main() {
   int a;
   cout << "Simple Parameterized Constructor For Prime Number Example Program In C++\n";

   cout << "\nEnter the Number:";
   cin>>a;

   // Object Creation For Class and Initiate Value from the user input
   Prime obj(a);

   // Call Member Function show()
   obj.show();

   // Wait For Output Screen
   getch();
   return 0;
}

Sample Output

Simple Parameterized Constructor For Prime Number Example Program In C++

Enter the Number:7
7 is Prime Number.

--
Simple Parameterized Constructor For Prime Number Example Program In C++

Enter the Number:10
10 is Not Prime Numbers.