Thread: infinite loop !

Hi, guys~

I just want to user input a number and then decide whether continue or not, but I met a infinite loop when testing it. my code is right below:

Code:

#include <iostream>

void main ()
{
    int x;
    while(1)
    {
        cout << "input a number: ";
        cin >> x;
        if (number==8)
        {
             break;
        }
    }
    //if break then go to next step;
}

it works fine when input a simply number, but that mess comes when your input a string like "relrejlre" etc. How to calm it down ???

look at the "atoi" (alpha to integer) function, an integer cannot handle input other than a number, and will crash, whereas if you use atoi ( stdio.h or stdlib.h i think ) it will convert to 0.

I think that is what you mean.

i ran nito the same problem as you. Good coding practice would be to put the loop in a try/catch block...but my program was for a buddy at work, so i left him an "easter egg" so to speak.

Code:

while (int theNumber<24&&int infiniteLoopCount<20)
{
std::cout<<"enter a number between 1 and 24"<<endl;
std::cin>>theNumber;
infiniteLoopCount++;
}
if (infiniteLoopCount<=10)
{
std::cout<<"Oh no! You've been caught in the INFINITE LOOP OF DEATH!!!\nNext time enter a number, have a nice day."<<endl;
//delete pointers and junk
exit(1);
}

now like i said, that's not exactly good coding practice, but the guy i made it for wasn't very computer savvy, and the look on his face was priceless . But if it's a formal app just go with the try/catch block....if you really want you can model it after the above while loop, then use a goto command to repeat it.

Code:

#include <iostream.h>

int main(void)
{
    int x;
    while (1)
    {
        cout << "input a number: ";
        cin >> x;
        if (!cin.good())
        {
            cin.clear();
            cin.ignore(10, '\n');
        }
        else if (x == 8) break;
    }   
}

This is better, IMHO:

Code:

#include <iostream.h>

int main(void)
{
    int x;
    while (1)
    {
        cout << "input a number: ";
        cin >> x;
        if (!cin.good())
        {
            //Clear all error flags
            cin.clear();
            //Remove all characters waiting to be read
            while (cin.rdbuf()->in_avail() > 0) cin.get();
        }
        else if (x == 8) break;
    }   
}

Originally posted by Hammer

Code:

#include <iostream.h>

int main(void)
{
    int x;
    while (1)
    {
        cout << "input a number: ";
        cin >> x;
        if (!cin.good())
        {
            cin.clear();
            cin.ignore(10, '\n');
        }
        else if (x == 8) break;
    }   
}

thanx boys and girls~

I just found cin.get and cin.ignore in my book, what about cin.good and cin.clear please £¿

it seems cin.clear and cin.good didnt works fine, what's the matter ? here is my code:

Code:

#include <iostream>

int i, j;

void main()
{
    while(1)
    {
    	cout << "please input a number: ";
        cin >> i;
        if (!cin.good())
        {
        	cin.clear();
        }
        else
        {
        	if(i==8)
         	{
          		cout << "good boy!";
          		break;
          	}
       }
    }
}