Remove character from string

Hi all,
the object is to write a function called say remchar that recieves a string say 'Hello' and a character 'o'.
The function should loop through the string look for the character passed 'o' if it exists which it does, rmove the character from the string and pass it pack to main to print out the modified string.

here is what I have so far and won't compile.

Code:

#include <stdio.h>

int main()
{
	char strin[10]={'H','e','l','l','o'};  	//init a char string called strin
	char chr = 'o';				//character var to pass to function to look for
						
	printf("\nstring before function call\t:>%s", strin);		//print the string pre call

	remchar(strin, chr);						//call remchar func 

	printf("\nstring after function call\t:>%s\n", strin);		//string post call

	return 0;
}

remchar(strin, chr)
{
int i;
	for(i = 0; strin[i] != '\0'; i++)	//start for loop
	{
		
	if(strin[i] == chr)		//test for character
			{
			strin[i] = strin[i] + 1 ; // write next character back to current position
			}
		}
}

The compile error is

subscripted value is niether array nor pointer

.
I haven't seen this one before!

Also can any one give me a bit of clarity on how to handle modifying arrays etc? I am not looking at pointers yet!

Any help is much appreciated

Thanks

You need to fix your function. You also need to declare it, or prototype it, before you use it. Look at your function. What type is strin? What about chr? Your function doesn't know, because you don't tell it.


Quzah.

Looks to me like he came from another programming language, probably a web one.

Hi quzah
ok thankyou understand that now I have made change to the function and declared so that it compiles. When run it prints Hellp because when 'o' is encountered I have added 1 to the value which makes 'o' become 'p' 'Hellp' how ironic!

This is where I probably require some clarity on updating the string before returning, because my test works by finding the character I am looking for its the how to manipulate this string is my issue given the objective stated earlier!

Here is my updated code to address the function issues!

Code:

#include <stdio.h>
void remchar(char *strin, char chr);
int main()
{
	char s[10]={'H','e','l','l','o'};  					//init a char string
	char c = 'o';								//character var to pass to function to look for
						
	printf("\nstring before function call\t:>%s", s);		//print the string pre call

	remchar(s, c);								//call remchar func 

	printf("\nstring after function call\t:>%s\n", s);		//string post call

	return 0;
}

void remchar(char *strin, char chr)
{
int i;
	for(i = 0; strin[i] != '\0'; i++)	//start for loop	
	{
		
	if(strin[i] == chr)			//test for character
			{
			strin[i] = strin[i] + 1;//this is wrong!!!!
			}
		}
}

again thanx for input and guidance

The variable strin is not a c-string just an array of char's. So testing for the '\0' terminator in remchar() will not work.
Kurt

Originally Posted by ZuK

The variable strin is not a c-string just an array of char's. So testing for the '\0' terminator in remchar() will not work.

Although it might look that way at first glance, such is not the case.

Originally Posted by Dave_Sinkula

Although it might look that way at first glance, such is not the case.

Yeah got it. It's declared to hold 10 char's so the remaining characters are initialized to '\0'.
Still a funny way to declare a c-string
Kurt

ok I have now made some changes to the function to process the incoming string write each element to an output string and copy the updated string back to original.

However when it runs I get out as follows

Hell?

where does the question mark come from?

can any one offer me some concise accurate answer?
can anyone comment constructively on whether this is a good way of handling this scenario and offer advise?

many thanks and here is the code

Code:

#include <stdio.h>
#include <strings.h>
void remchar(char *strin, char chr);
int main()
{
	char s[10]={'H','e','l','l','o'};  	//init a char string
	char c = 'o';				//character var to pass to function to look for
						
	printf("\nstring before function call\t:>%s", s);		//print the string pre call

	remchar(s, c);							//call remchar func 

	printf("\nstring after function call\t:>%s\n", s);		//string post call

	return 0;
}

void remchar(char *strin, char chr)
{
int i, j=0;
char cupdate[10];				//temp storage for updated string

	for(i = 0; strin[i] != '\0'; i++)	//start for loop
	{
		
	if(strin[i] != chr)			//check its not the char i want
			{
			cupdate[j] = strin[i];	//copy element to temp string 
			j++;			//move along the index one
			}
	else
			{
			;			//do nothing
			}
	}
j++;						//move along the index one
cupdate[j] = '\0';				//terminate the string
printf("strin = %s\tcupdate = %s", strin, cupdate);	//show what its doing
strcpy(strin, cupdate);					//copy updated string back to original
}

Don't increment j after the loop. It's already where you want it to be to null terminate the string.

[edit]And it's <string.h>, not <strings.h>.

Thankyou Dave_Sinkula
for your advice and guidance.

Consider also that you can modify the original string in place, thus getting away from using a temporary.

Code:

#include <stdio.h>

void remchar(char *s, char chr)
{
   int i, j = 0;
   for ( i = 0; s[i] != '\0'; i++ ) /* 'i' moves through all of original 's' */
   {
      if ( s[i] != chr )
      {
         s[j++] = s[i]; /* 'j' only moves after we write a non-'chr' */
      }
   }
   s[j] = '\0'; /* re-null-terminate */
}

int main()
{
   char text[] = "The quick brown fox jumps over the lazy dog.";
   printf("before : %s\n", text);
   remchar(text, 'o');
   printf("after  : %s\n", text);
   return 0;
}

/* my output 
before : The quick brown fox jumps over the lazy dog.
after  : The quick brwn fx jumps ver the lazy dg.
*/

Ahh That is the kind of guidance I was looking for Dave_Sinkula, thankyou, the copy inplace looks a more economic way of coding it, that is what I wanted to do but new not how to express it or how to code it, I will use that example now!

Cheers