Need help with this for loop please, can't make it work.

[hydroJ]

it works through the cout << test print for smallDigitLoop 2. but can't get the rest of the code to work they way I want to. trying to compare all the values in the array and store the largest digit to compareIntGreater.

thanks for any advice.

void printSmallestLargestDigit(int iVal) {
	
	int tempInteger = iVal;
	int	count = 0; 
	int countTwo = 0;
	int modifyIValTwo = iVal;
	int modifyIVal3 = iVal;

cout << "test print for smallDigitLoop" << endl;	
	do {									// Determine the number of digits of the integer

         tempInteger = tempInteger / 10;

         count++;
		 countTwo++;

     } while (tempInteger != 0);

	

	int* digit = new int[count];			// Dynamically allocating array to store all the digits

	int* digitTwo = new int[countTwo];

	for(int index = count - 1; index >= 0; index--) {		// Find the remainder, then move 1 place to the left

        digit[index] = modifyIValTwo % 10;

        modifyIValTwo = modifyIValTwo / 10;

    }

	cout << "test print for smallDigitLoop 2" << endl;
	
	for(int indexTwo = countTwo - 1; indexTwo >= 0; indexTwo--) {
		
		digitTwo[indexTwo] = modifyIVal3 % 10;

        modifyIVal3 = modifyIVal3 / 10;

		
		if(compareIntGreater > digitTwo[countTwo]) {
		return;
		} else if(digitTwo[countTwo] > digitTwo[countTwo--]) {
		  compareIntGreater = digitTwo[countTwo -1];
		  return;
		} else(digitTwo[countTwo] < digitTwo[countTwo--]);
		  compareIntGreater = digitTwo[countTwo--];
	}
cout << "test print for smallDigitLoop 3" << endl;	
	cout << "Greatest digit: " << compareIntGreater << endl;

	delete [] digit;
	delete [] digitTwo;

    digit = 0;
	digitTwo = 0;
	
return;
}

[owX8T05o]

I don't know if the it's the problem but,

When you do digitTwo[countTwo--] --> countTwo = countTwo-1

Since countTwo is used in the loop maybie it's the reason ... I'd put debugging points to be sure.

[owX8T05o]

Ok i've run your code. The problem (maybie) is the return in the code :

if(compareIntGreater > digitTwo[countTwo]) {
return;
} else if(digitTwo[countTwo] > digitTwo[countTwo--]) {
compareIntGreater = digitTwo[countTwo -1];
return;
} else(digitTwo[countTwo] < digitTwo[countTwo--]);
compareIntGreater = digitTwo[countTwo--];

return will escape from main.
I've tried to comment these lines and the execution goes trougth the second loop.
Maybie you meant break and not return ?

I've not tested the code so far, can't tell if it works properly.

Bye

[chenqi07]

Don't write codes like this.
(digitTwo[countTwo] > digitTwo[countTwo--])
The value of this statement is always false as it is equal to this.

(digitTwo[countTwo] > digitTwo[countTwo]);
countTwo--; 

Maybe you wanted to write (digitTwo[countTwo] > digitTwo[--countTwo]) ;
However, this is also dangerous because we don't know exactly how the compiler will deal with this statement, the right side will be calculated first, or the left side?

[Disch]

else if(digitTwo[countTwo] > digitTwo[countTwo--])

Never do this. There's no way of knowing whether or not the -- operator will be evaluated before the first countTwo expression is evaluated. You get undefined behavior.

That is... if you have the below code:

int a = 1;
if( foo[a] > foo[a--] ) // <- 

that line might compare foo[0] to foo[1]. Or it might compare foo[1] to foo[1]. There's no way to know which you'll get.


EDIT: chenqi beat me to it, although note the behavior is undefined so it won't necessarily always be true. The actual result you get is completely unreliable.