Leap Year code 99% right but

The_Kew_Tour

Here is a code I have in place for sorting out Leap Years. It Works for every year bar 1700, 1800, 1900. Works for 1600 and 2000. Basically any years bar start of decades not ending in 4s

Can anyone help

if((year % 4 == 0 && year % 100 != 0) || year % 400==0) {
return true;
}

else{
return false;
}


}

Procasinator

1700, 1800, 1900 were not leap years. So when you say it doesn't work, do you mean it reports them years as leap ones?

Seridisand

if((year % 4 == 0 && year % 100 != 0) || year % 400==0) {
            return true;
        }
       
        else{
            return false;
        }
        
        
    }

This evaluates to year divide by 4/remainder =0, AND year divide by 100/remainder NOT = 0 OR year divide by 400/remainder = 0:

1700 / 4 = 0 True (Remainder 0)
1700 /100 NOT = 0 False (Remainder 0)
1700 / 400 = 0 False (Remainder 100)
(True AND False) OR False == ALWAYS FALSE

1800 / 4 = 0 True (Remainder 0)
1800 /100 NOT = 0 False (Remainder 0)
1800 / 400 = 0 False (Remainder 200)
(True AND False) OR False == ALWAYS FALSE

ChRoMe

What language is this? I suppose what I'm really asking is why are you doing this by hand?

Graham

ChRoMe wrote: »

I suppose what I'm really asking is why are you doing this by hand?

I would hazard a guess that it's homework. It doesn't appear to be the usual 'please complete my entire assignment' type of question though which is probably a good sign.

Trojan

ChRoMe wrote: »

What language is this?

Looks like C to me.

It seems a bit early in the academic year for homework like this, but has all the hallmarks.

Fair play to OP for not doing the usual "do it for me" plea.

Graham

Level 5 City and Guilds exam prep??

Trojan wrote: »

Fair play to OP for not doing the usual "do it for me" plea.

+1

Procasinator

Trojan wrote: »

Looks like C to me.

It seems a bit early in the academic year for homework like this, but has all the hallmarks.

Fair play to OP for not doing the usual "do it for me" plea.

It's a C based language anyhow, but it could easily be a valid fragment from Javascript, Java, C#, C++, e.t.c.

ChRoMe

Procasinator wrote: »

It's a C based language anyhow, but it could easily be a valid fragment from Javascript, Java, C#, C++, e.t.c.

Yeah saying it looks like C based syntax really doesn't help narrow it down!

If its homework fair enough, however if its not, you really should be using a proper time lib (such as Joda for Java) instead of calculating this stuff by hand.

Graham

I think most of the OP's recent dev posts have been Java related.

The_Kew_Tour

I don't want it done. Its a past exam paper one thankfully I wont be doing again.

I was just asking for help that is all.

Graham

The_Kew_Tour wrote: »

I don't want it done. Its a past exam paper one thankfully I wont be doing again.

I was just asking for help that is all.

I think that had been established in your absence TKT

BrokenArrows

It all seems to work fine for me.

Can you explain further as to why you think your code is not working?


Spoiler below is how .NET's IsLeapYear(int year) method works.

if ((year % 4) != 0)
{
return false;
}
if ((year % 100) == 0)
{
return ((year % 400) == 0);
}
return true;

The_Kew_Tour

its actually working fine for me now. Thanks guys. it was me that was wrong in first place.