I have problem with my code that deals with friend >
operator but I can't seem to be able to fix it.
I added the friend bool operator > (const my_int& c1, const my_int& c2);
code and that I know is right but the in the main class where I tried to implement it is a bit wrong and don't know how to fix.
#include <iostream>
#include <cmath>
using namespace std;
//*********************************************************
// Function: my_int
// Purpose: Constructor initializes the val to x
// Params: x - the value for the val
// Calls: none
// Uses: none
//*********************************************************
//my_int::my_int(int x);
//*********************************************************
// Function: my_int
// Purpose: Constructor initializes the val to 0
// Params: none
// Calls: none
// Uses: none
//*********************************************************
//my_int::my_int();
//*********************************************************
// Function: my_int
// Purpose: Constructor initializes the val to x
// Params: x - the value for the val
// Calls: none
// Uses: none
//*********************************************************
//my_int::my_int();
//*********************************************************
// Function: set
// Purpose: Sets the val to x
// Params: x - the new value for the val
// Calls: none
// Uses: none
//*********************************************************
// void my_int::set(int x);
//*********************************************************************
// Function: input
// Purpose: reads and stores a value from inp. if fin is a input
// stream, then fin is already connected to a file.User enters
// a value and ask the user to re-enter the data if the
// user enters an incorrect value.
// Params: inp -- the input stream
// Calls: none
// Uses: istream
//*********************************************************************
//void my_int:: input(istream& inp);
//*********************************************************************
// Function: output
// Purpose: display the val on fout. if fout is a output stream
// then fout is already connected to a file
// Params: fout -- the output stream
// Calls: none
// Uses: ostream
//*********************************************************************
//void my_int::output(ostream& fout);
//*********************************************************
// Function: get_int
// Purpose: returns the val
// Params: none
// Calls: none
// Uses: none
//**********************************************************
// int my_int::get_int()
//*********************************************************
// Function: is_prime
// Purpose: object num contains a valid positive value
// returns true if num is prime; otherwise
// returns false
// Params: num - the value to be checked for prime
// Calls: sqrt
// Uses: cmath
//*********************************************************
// bool is_prime(const my_int& num);
class my_int
{
public:
my_int(int x);
my_int();
void set(int x);
void input(istream& inp);
void output(ostream& fout) const;
int get_int() const;
friend bool operator >(const my_int& c1, const my_int& c2);
private:
int val;
};
bool is_prime(const my_int& num);
int main()
{
my_int value1;
value1.input(cin);
value1.output(cout);
if (is_prime(value1))
cout << " is a prime number \n";
else
cout << " is not a prime number \n";
return 0;
}
my_int::my_int(int x)
{
val = x;
}
my_int::my_int()
{
val = 0;
}
void my_int::set(int a)
{
val = a;
}
void my_int::output(ostream& fout) const
{
fout << " The value is equal to " << val << endl;
}
int my_int::get_int() const
{
return val;
}
bool operator >(my_int& c1, my_int& c2)
{
if (c1.val > c2.val)
return (true);
else
return (false);
}
void my_int::input(istream& inp)
{
cout << "Enter a positive value greater than 1 ";
inp >> val;
while (val <= 1)
{
cout << "Entered an Invalid value \n";
cout << "Enter a positive value greater than 1 \n";
inp >> val;
}
}
//num has been given a value and returns true if the value is a
//prime number and false otherwise
bool is_prime(const my_int& num)
{
double limit;
int n; //divisor
bool prime= true;
limit = sqrt(static_cast<double>(num.get_int()));
n = 2;
while (n <= limit && prime)
{
if (num.get_int() % n == 0)
prime = false;
else
n++;
}
return prime;
}
You need something like this:
bool operator > (my_int& c1, my_int& c2)
{
return c1.val > c2.val;
}
Then name of the data members is val
, their type is int
. Calling c1.int
makes no sense in C++. And the pattern
if (x)
return true;
else
return false;
is long and unidiomatic. You can just return x;
.
Besides that, you should consider passing const
references. This will allow you to bind to temporary values:
bool operator > (const my_int& c1, const my_int& c2) { ... }
You need to modify both the declaration and the definition.
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