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scanning char array for \0 problem

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Join Date: Jan 2008

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Matt You

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scanning char array for \0 problem

Jan 22nd, 2008

I'm trying to make a function that can scan a char array, and finish it's business when it comes to a '\0'. so here is the for loop i came up with:

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for( i=0 ; charArray[i] != '\0' ; i++ )
for( i=0 ; charArray[i] != '\0' ; i++ )

But here is an example of entered data: "1234 432"

It seems to end the loop at the space. So are spaces and null characters similar? how can i differentiate between the two so that it keeps going right through a space and only stops at a null?

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Join Date: Sep 2004

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Narue

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Re: scanning char array for \0 problem

Jan 22nd, 2008

>So are spaces and null characters similar?
No, not at all.

>how can i differentiate between the two
You don't need to differentiate between the two. You need to figure out why your code is stopping when you don't think it should. We can help, but you need to post more code. Preferably a complete program that exhibits the problem.

I'm here to prove you wrong.

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Matt You

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Re: scanning char array for \0 problem

Jan 22nd, 2008

here ya go:

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#include <stdio.h>
 
int dummy;
 
int stringSplitter(char arrayToSplit[], int arraySize);
 
int main()
	{
	char userString[20];
 
	printf("Enter 3 numbers, seperated by spaces: ");
	scanf( "%s", userString);
 
	stringSplitter(userString, 20);
 
    scanf("%d", dummy);
    }
 
int stringSplitter(char arrayToSplit[], int arraySize)
	{
	unsigned int i;
 
	for( i=0 ; arrayToSplit[i]!='\0' ; i++ )
		{
		printf("%c", arrayToSplit[i]);			
 
		}	
 
	}
#include <stdio.h>

int dummy;

int stringSplitter(char arrayToSplit[], int arraySize);

int main()
	{
	char userString[20];

	printf("Enter 3 numbers, seperated by spaces: ");
	scanf( "%s", userString);
	
	stringSplitter(userString, 20);
	
    scanf("%d", dummy);
    }

int stringSplitter(char arrayToSplit[], int arraySize)
	{
	unsigned int i;

	for( i=0 ; arrayToSplit[i]!='\0' ; i++ )
		{
		printf("%c", arrayToSplit[i]);			

		}	

	}

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Duoas

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Re: scanning char array for \0 problem

Jan 22nd, 2008

Ah, the loop ends at the space because the string ends at the space. scanf stops reading input at spaces. So when you enter "1234 432" the userString gets "1234", and " 432" is left waiting to be read.

If you want to get a string from the user try using fgets().

Good luck.

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Matt You

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Re: scanning char array for \0 problem

Jan 22nd, 2008

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Originally Posted by Duoas

Ah, the loop ends at the space because the string ends at the space. scanf stops reading input at spaces. So when you enter "1234 432" the userString gets "1234", and " 432" is left waiting to be read.

If you want to get a string from the user try using fgets().

Good luck.

Thank you! I never would have figured that out. It all works the way it should now.