Help on OO leap year calculator

[Protoman]

Hi!!! I need some help on a project I'm that calculates leap years; I'm
getting errors that I have no idea what they mean; here's the code:

#include <iostream>
#include <cstdlib>
using namespace std;

class Year
{
public:
Year(int y=0):year(new int) *year(y){}
~Year(){delete year;}
Year(const Year& rhs)*year(rhs.* year){}
Year operator=(const Year& rhs)
{
if(this!=&rhs)
{
*year=rhs->year;
delete year;
}
else return this;
}
void SetYear(int y):year(new int),*year(y){}
int GetYear()const{ return *year;}
bool IsLeapYear(cons t Year& y)const
{
if(y->year%400==0& &y->year%4==0)
return true;
else if(y->year%100)
return false;
else return false
}
friend ostream& operator<<(ostr eam& os,const Year& y);
private:
int* year;
};

ostream& operator<<(ostr eam& os,const Year& y)
{
os << y.GetYear();
return os;
}
}
int main()
{
int date;
for(;;)
{
cout << "Enter a year: " << endl;
cin >> date;
Year year(date);
if(year.IsLeapY ear)
cout << year << " is a leap year. " << endl;
else
cout << year << " is not a leap year. " << endl;
bool cont;
cout << "Continue?[1=yes|0=no]: " << endl;
cin >> cont;
if(cont==true)c ontinue;else break;
system("PAUSE") ;
return 0;
}
And as a side note, it's not letting me use constructor inizilization
syntax. Can you help me (this isn't homework)? Thanks for your help!!!

[Daw]

And what erros u get?

[Daw]

And I'm sure this _is_ a school work ;>

[Protoman]

No it's not; my friend, Jonathon Mastron at BIOLA, asked me to it for
him. My school work is trig stuff, not calendars and dates. Just help
me please.

[Protoman]

OK, I fixed it; it compiles and runs now; here's the code:

#include <iostream>
#include <cstdlib>
using namespace std;

class Year
{
public:
Year(int y=0): year(y){}
~Year(){}
Year(const Year& rhs):year(rhs.y ear){}
Year operator=(const Year& rhs)
{
if(this!=&rhs)
year=rhs.year;
return *this;
}
void SetYear(int y){year=y;}
int GetYear(void)co nst{return year;}
bool IsLeapYear(void )const
{
if(year%400==0& &year%4==0)
return true;
else if(year%100)
return false;
else return false;
}
friend ostream& operator<<(ostr eam& os,const Year& y);
private:
int year;
};

ostream& operator<<(ostr eam& os,const Year& y)
{
os << y.GetYear();
return os;
}

int main()
{
int date;
for(;;)
{
cout << "Enter a year: " << endl;
cin >> date;
Year year(date);
if(year.IsLeapY ear())
cout << year << " is a leap year. " << endl;
else
cout << year << " is not a leap year. " << endl;
bool cont;
cout << "Continue?[1=yes|0=no]: " << endl;
cin >> cont;
if(cont==true)c ontinue;else break;
}
system("PAUSE") ;
return 0;
}

Anyway I can make it more efficient? And other than calculating leap
years, what other uses can I have for this class? And what other ops
should I overload? Thanks for the help!!!

[Protoman]

I'm trying to overload operator>>, but my program keeps aborting;
here's the code for operator>>:

istream& operator>>(istr eam& is,const Year& y)
{
is >> y.year;
return is;
}

Why does it keep aborting?

[Raymond Martineau]

On 18 Sep 2005 15:35:16 -0700, "Protoman" <Pr**********@g mail.com> wrote:

I'm trying to overload operator>>, but my program keeps aborting;
here's the code for operator>>:

istream& operator>>(istr eam& is,const Year& y)
{
is >> y.year;
You are trying to modify a const value. In fact, the const qualifier is
not appropriate for this kind of function.
return is;
}

Why does it keep aborting?

If it aborts at that region, then perhaps there might be a logic error in
your code. Best to find some form of debugger.

[Protoman]

I fixed it and it works.

[benben]

to encapsulate, you should really make the leap year identification a
non-friend, non-member, standalone function.

like:

bool is_leapyear(Yea r year){/*...*/}

ben

[Greg]

Protoman wrote:

OK, I fixed it; it compiles and runs now; here's the code:
..
bool IsLeapYear(void )const
{
if(year%400==0& &year%4==0)
return true;
else if(year%100)
return false;
else return false;
}

This function is clearly not correct. It will return false for nearly
every year that is a leap year. The first clue that something is amiss,
is the fact that it tests whether a year is divisible by 4 after it
knows it is divisible by 400. Anyway, here is a corrected version:

bool IsLeapYear() const
{
if ( year%4 ) // not divisible by 4
return false;
if ( year%100 ) // not a century year
return true;
if ( year%400 ) // not a fourth century
return false;
return true;
}

Also, I would work on writing more readable code. The layout of the
code in the original program is atrocious. Do spaces cost extra?

Greg