need help with arrays

[CoW]

ok... i cant quite figure out what the problem is with this program....

[SHELL]
#include <iostream.h>
#include <stdlib.h>
#include <ctype.h>
long date[3];
int dateValid();
int monthState();


int main()
{
cout << "Please enter a date dd/mm/yyyy: ";
cin >> date[0] >> date[1] >> date [2];
dateValid();
cout << date[1];
monthState();
cout << date[2];
system("PAUSE");
return 0;
}

int dateValid()
{
for (int x=0; x<3; x++)
{
if (isdigit(date[x]))
cout << "Please enter a date dd/mm/yyyy: ";
else
cout << "Entry Valid\n";
};
};

int monthState();
{
int x= date[0];
char month[12] =
{
"January", "February", "March",
"April", "May", "June",
"July", "August", "September",
"October", "November", "December"};

cout << month[x];
};
[/SHELL]

and whenever i complile it i get this beautiful little error

initialization to `char' from `const char *' lacks a cast

12 times...

what the heck is going on?

[joe_bruin]

Originally posted by CoW
and whenever i complile it i get this beautiful little error 12 times...

12 times, eh?
have you looked at the line number the compiler complains about? your "char month[12]" is a single array of 12 characters, but you're trying to assign to it 12 character arrays;

try:
char *month[12]

[CoW]

ok, no more compile errors (yay!)

but now after dateValid() runs the program crashes....

[joe_bruin]

well, you have several bugs in your program.

your use of isdigit() is incorrect.
your monthState() has an off-by-one error.
i think the way you cin dates is wrong as well, but it's been quite a while since i've used cin, so i'm not sure about it.

try writing a small component of the program at a time. compile, test, fix, test, fix, test, ..., and when you're confident it works, go on to the next part.

[CoW]

Originally posted by joe_bruin
well, you have several bugs in your program.

your use of isdigit() is incorrect.
your monthState() has an off-by-one error.
i think the way you cin dates is wrong as well, but it's been quite a while since i've used cin, so i'm not sure about it.

try writing a small component of the program at a time. compile, test, fix, test, fix, test, ..., and when you're confident it works, go on to the next part.

feel free to explain how my isdigit() use is wrong, because i can't see how im using it improperly...

as for month state... i cant see anything wrong with it...

my cins are fine.

[sde]

int isdigit() returns a non-zero if true and a zero if false.

either way it returns an integer.

now i'm not sure on this but perhaps test for zero isntead of boolean.

if (isdigit(date[x]) == 0)  
cout << "Please enter a date dd/mm/yyyy: ";  
else  
cout << "Entry Valid\n";  
};

i'm just guessing here based on this documentation: http://www.mkssoftware.com/docs/man3/isdigit.3.asp

[sde]

also, after looking at it .. if your code is correct, then it appears your logic is wrong:

if (isdigit(date[x]))
{
  cout << "Please enter a date dd/mm/yyyy: ";  
  else  
  cout << "Entry Valid\n";  
};  // should there be a ';' at the end of this line?

assuming isdigit would return true/false with that if statement, if it 'is a digit' then it would ask you to please enter a date .. and if it 'is not a digit' then it would say entry valid.

also, that semi colon at the end of the '}' .. are you sure that goes there? i really don't know . just doesnt' look right.

i think it should be more like this:

if (!isdigit(date[x]))
{
  cout << "Please enter a date dd/mm/yyyy: ";  
}
else
{
  cout << "Entry Valid\n";  
}

p.s. i'm no c++ expert .. so take my advice with a grain of salt .. just tryin to help if i can.

[CoW]

what the heck... everything compiles ok, and i replaced the isdigit statement with yours and tahts working fine, but the date[2] always returns as "10" in the dateValid() function.... and then the console app crashes..

[joe_bruin]

Originally posted by CoW
feel free to explain how my isdigit() use is wrong, because i can't see how im using it improperly...

sde is off in this case, your test did work (his correction did, too). but read the documentation on it very carefully, you are not using it correctly. here's a hint from the link sde included:
"isdigit() - tests if character is a digit"

the semicolon at the end of the if statement was also technically wrong, but in this case it did not interfere with anything (it's just an empty statement).

as for month state... i cant see anything wrong with it...

oh? try entering '12' for the month and see what happens. that is, when you fix your cin.

my cins are fine.

not quite. i'd advice you to look at the values of date[1] and date[2] and figure out why they are incorrect.

[sde]

thanks for checkin that joe .. maybe i should put permanent disclaimers in my sig

[CoW]

thanks for the help guys, i dicided to drop the isdigit thing all together as it only works for values 1 thru 9...

heres the finished (working!) code.
[SHELL]
#include <iostream.h>
#include <stdlib.h>
#include <ctype.h>

int date[3];
int dateValid();
int monthState();

int main()
{

cout << "Please enter a date dd/mm/yyyy: ";
cin >> date[0];
cin >> date[1];
cin >> date[2];
dateValid();
cout << date[1] << " ";
monthState();
cout << date[2];

system("PAUSE");
return 0;
}


int dateValid()
{

if (date[0] > 31 || date[0] < 1)
cout << "Invalid Entry\n";
else
cout << "Entry Valid\n";

if (date[1] > 12 || date[1] < 1)
cout << "Invalid Entry\n";
else
cout << "Entry Valid\n";

if (date[2] > 2020 || date[2] < 1990)
cout << "Invalid Entry\n";
else
cout << "Entry Valid\n";
};


int monthState()
{
int x= date[0];
char *month[12] = {"January", "February", "March",
"April", "May", "June",
"July", "August", "September",
"October", "November", "December"};

cout << month[x] << " ";
};
[/SHELL]

[sde]

Originally posted by sde
thanks for checkin that joe .. maybe i should put permanent disclaimers in my sig

haha .. i didn't really think about it but i think my sig is pretty much just that.

[joe_bruin]

finished and working? seems to have a bunch of errors in it.

why does it print "February" when i enter "1" for the month?
if i enter "1/1/2000" it still doesn't work.

you have the following warnings.:
test.cpp: In function `int dateValid ()':
test.cpp:43: warning: no return statement in function returning non-void
test.cpp: In function `int monthState ()':
test.cpp:55: warning: no return statement in function returning non-void

those semicolons at the end of your functions (ex "};") don't belong there (like sde pointed out previously).

i don't mean to be hard on you, i'm just telling you what is wrong and hoping you learn by fixing it.