>It looks as if you are automatically assuming that Z is an integer
That's a reasonable assumption seeing as how Z was declared as int.
>When it's not an integer, but it's treated as one, you could end up in some sorta loop further down in your program.
The problem is with cin. The >> operator of cin will figure out what type the object is and convert the data from the standard input stream to that type. If there's no conversion then cin will leave the unconverted data in the stream and enter a failure state. This is a common problem with loops like this:
int number;
while ( cin>> number )
cout<< number <<endl;
If a letter is entered, this will be an infinite loop because cin will continue to fail on the invalid data in the stream. The solution is to remove the offending input and clear the streamor read all data as a string and parse it for error handling. The latter is easy and the former can be done (rather naively) like this:
#include <iostream>
using namespace std;
bool get_number ( int& number )
{
while ( !( cin>> number ) ) {
if ( cin.eof() )
return false;
else {
char ch;
cin.clear();
cout<<"Invalid input, please try again: ";
while ( cin.get ( ch ) && ch != '\n' )
;
}
}
return true;
}
int main()
{
int number;
while ( get_number ( number ) )
cout<< number <<endl;
}
>to force z to be treated as an integer.
It's too late at that point. The issue isn't with Z being treated as an integer, but with cin's >> operator returning a failure status.
>there might be a built-in function (I'm not exactly sure) that determines whether a value isInt()
Provided the value is a string, you can try to convert it to an integer with atoi (yuck) or strtol (better). If the conversion succeeds then it's an integer, otherwise not. But this is a moot point if you're trying to read and convert input with the same function call, such as scanf or cin's >> operator.
>You would look at the ASCII equivalent of the value and see if it is an integer range or a character range.
Or just use
if ( Z >= '0' && Z <= '9' )
Since the standard requires digits to have adjacent values regardless of the character set. Or better yet, include and say
if ( std::isdigit ( Z ) )
But that only handles one character. For numbers longer than a single digit you need a loop. Once again, the point is moot because cin will try to convert the input to an integer before you can get your hands on it. By then the damage has presumably already been done.
>That way the infinite loop will run 2-4 times faster!
Kind of like trying to optimize your idle system process, no? :D
