# Simple Constructor Example Program For Find Prime Number 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.

## Simple Program  Find Prime Number Algorithm/Steps:

• STEP 1:  Start the program.
• STEP 2:  Declare the class as Prime with data members,
•                   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() {
// Constructor code
}

//... other Variables & Functions
}``````

## Example Program

``````/*  Example Program For Simple Constructor Example Program For Prime Number Overloading In C++
little drops @ thiyagaraaj.com

Coded By:THIYAGARAAJ MP             */

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

using namespace std;

// Class Declaration

class prime {
//Member Varibale Declaration
int a, k, i;
public:

prime(int x) {
a = x;

k = 1;
{
for (i = 2; i <= a / 2; i++)
if (a % i == 0) {
k = 0;
break;
} else {
k = 1;
}
}
}

void show() {
if (k == 1)
cout << "\n" << a << " is Prime Number.";
else
cout << "\n" << a << " is Not Prime Numbers.";
}
};

//Main Function

int main() {
int a;
cout << "Enter the Number:";
cin>>a;

// Object Creation For Class
prime obj(a);

// Call Member Functions
obj.show();
getch();
return 0;
}``````

## Sample Output

``````Enter the Number:7
7 is Prime Number.``````