Help with try catch block

I have a while loop, within it I get an integer variable...the problem is if the user enters a character the loop goes into a cycle infinitely, my work around was kind of humorous...i added one to a loop count and if it went over 20 in one shot i killed the loop and went on with an error, cleaned up and exited. But, i want to formulate a try catch block so that i can restart the loop safely to get a number instead of a letter....any ideas?

a stripped down example would work great, i've seen tuturials but they're examples are too vague...i cna't get a grip on it

There are couple ways of doing this. Unfortunately I don't really have the time to get them working but hopefully I'll get you mind going in the right direction.

If you are looking for integers that are more than one digit long, I would suggest using a while loop to take in the input one character at a time which is inside your main while loop. If it checks out to be a number add it to a string. If you get to the end of the input and you have found only number ... change the string to an integer and exit the loops. If you find a character, jump out of the first loop and restart the program.

here is some pseudo code to help

Code:

int finalNum
int check
char input
string number

while (true)

   while (more input)
      check input for integer
      if integer 
         concat to string
      else
         check = -1
         break loop

   if check != -1
      break out of loop

Yes the code is kinda tedious however it's also crash proof. If you write it correctly you don't have to worry about what the user enters because you will have account for any stupidity by them.

Show us some code that you have attempted. I am unclear what you are trying to ask.

the problem is if the user enters a character the loop goes into a cycle infinitely

Greetings,
Why not use the assert() so that when a character is inputted it will terminate the program. But I would try posting your code just so we can have a better idea of what you have.

I hope this helps and post your code pls.

Code:

if (!cin)
{
  //[print error msg]
  cin.clear();
  cin.ignore(numeric_limits<streamsize>::max(),'\n');
}
//go on...

(Edit: don't forget to #include <limits>)

Code:

int company=25;
int infiniteLoopCout=0;

...

	while (company>24&&infiniteLoopCount<10) 
	{
		std::cout<<"Which Company Is The Part For?"<<endl;
		std::cout<<"		AMT		0"<<"	||	Mercury		13"<<endl;
		std::cout<<"		Barber		1"<<"	||	Misc.		14"<<endl;
		std::cout<<"		BeloitCP	2"<<"	||	Modern		15"<<endl;
		std::cout<<"		Borg		3"<<"	||	Nissan		16"<<endl;
		std::cout<<"		Bosch		4"<<"	||	Packard		17"<<endl;
		std::cout<<"		Camcar		5"<<"	||	Phil		18"<<endl;
		std::cout<<"		Colt		6"<<"	||	Simmons		19"<<endl;
		std::cout<<"		Durst		7"<<"	||	SSI		20"<<endl;
		std::cout<<"		Enkel		8"<<"	||	Tradewind	21"<<endl;
		std::cout<<"		Goex		9"<<"	||	Warman		22"<<endl;
		std::cout<<"		Isthmus		10"<<"	||	Warner		23"<<endl;
		std::cout<<"		Kulasik		11"<<"	||	Witco		24"<<endl;
		std::cout<<"		Lear		12"<<"	||"<<endl;
		std::cout<<"\nEnter Choice Here:";
		std::cin>>company,cin.get();
		std::cin.clear();
		infiniteLoopCount++;
	}
	if (infiniteLoopCount>=10)
	{
		/*normally you would use a try/catch block for this...but what the hey, lyall could use a little entertainment...
		plus i'd like to see what his reaction would be, considering he doesnt use a computer all that much...*/
		system("cls");
		ErrorHandler("Oh No!!!\nYou've Been Caught In The Infinite Loop Of Death!!!\n\nNext Time Enter The Number Of The Company, Have A Nice Day\n");
	}
}

that's the original code, i'm going to try that last suggestion though

well that last suggestion didn't work....here's the problems:
MING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(162) : error C2275: 'streamsize' : illegal use of this type as an expression
C:\Program Files\Microsoft Visual Studio\VC98\INCLUDE\iosfwd(21) : see declaration of 'streamsize'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(162) : warning C4003: not enough actual parameters for macro 'max'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(162) : error C2589: '(' : illegal token on right side of '::'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(162) : error C2059: syntax error : '::'

anyhow i'm still open for suggestions...thanks much to those who have tried.

>anyhow i'm still open for suggestions...
Make sure you included the header <limits>.

-Prelude

oops, forgot the header
im at work right now, and the programs at home, i'll check it there. thanks for telling me about that, i must have missed his edit

well i did include limits...here's my code as it stands now...with errors in compiling:

Code:

		if (!cin)
		{
			cin.clear();
			cin.ignore(numeric_limits<streamsize>::max(),'\n');
			company=25;
		}

errors:

\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(157) : warning C4003: not enough actual parameters for macro 'max'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(157) : error C2589: '(' : illegal token on right side of '::'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(157) : error C2143: syntax error : missing ')' before '::'
c:\DREW\PROGRAMMING\C++\PROGRAMS\Part Finder Fixed\Part Finder Fixed.cpp(157) : error C2059: syntax error : ')'

thanks again for all your time

Solution:

Code:

#ifdef max
  #undef max
#endif
#include <limits>

or just forget about the numeric_limits thing and replace it with 10000 or something.
But numeric_limits<streamsize>::max() looks more professional.

ok, got all that worked out, but i had to change some of my logic around...and it's giving me a quirk, when entering in the company variable i have to hit enter twice, this is because i removed cin.get() because it forced the if (!cin) part to not work correctly, does anyone have any suggestions on how to fix this? (note i can't use cin.get or getline because it's an integer variable)

Code:

while (company>24)
{
...
		std::cout<<"\nEnter Choice Here:";
		std::cin>>company;
		if (!cin)
		{
			cin.clear();
			cin.ignore(numeric_limits<streamsize>::max(),'\n');
			company=25;
			cout<<"\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n"; //cls messes up so just do blank lines
		}
		cin.get();
		cin.clear();
	}

??