# 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.
``````