Blank char counter in C

Question

I am trying to create a small function that returns the number of spaces in a Char* variable using the C language.

Let's say I have this string :"hello hello hello". I want the function to return 2. This is the code I have so far:

int blankcounter(char* pline)
{                              
  int i=0;                  
  int counter = 0;            
  while (pline[i] != '\0')       
  {                               
    if (pline[i++] ==' ')
      counter++;
  }
  return counter;
}

the source that i am reading from is a txt file and 1 correction that i have to add is that the code that i posted indeed works but got 1 downside: if for example i want to read : "hello whats up "i want my function to be able to return 2 but it returns 3 because of the space that appears just after the wordup do u have any suggestion for me so it will return 2 ?

Works for me. It will only check for literal spaces. You could use `isspace` to be more general. — Matthew Flaschen, Aug 21 '10 at 20:04
for some reason it doesnt work for me ... the counter stays on 0 even tho i got some spaces — Nadav, Aug 21 '10 at 20:09
How are you determining that? You should use `const char*` to point at strings. Also, `counter`, `i`, and the return value should all be unsigned types (negative values don't make sense). And you might turn the `while` into a `for`, though that's arguably just a preference. — GManNickG, Aug 21 '10 at 20:11

score 2 · Accepted Answer · edited May 23 '17 at 11:48

2

I suspect you would not want to count leading spaces too " hello whats up" should return 2 as well right?

I can propose 2 solutions. First is to trim all spaces before you start counting them How do I trim leading/trailing whitespace in a standard way?.

The second is to adjust the start and end point of your loop to the first and last non-space characters and then perform the count:

int start=0;  
int end = strlen(pline);  
int i=0;  
while (pline[i++]==' ') start++;  
i=end-1;  
while (pline[i--]==' '&& i >= 0) end--;  
for (i=start; i<end; i++) { your count procedure}

edited May 23 '17 at 11:48

Community

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answered Aug 21 '10 at 20:35

spbfox

939
4
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the source that i am reading from is a txt file and 1 correction that i have to add is that the code that i posted indeed works but got 1 downside: if for example i want to read : `"hello whats up "`i want my function to be able to return 2 but it returns 3 because of the space that appears just after the word `up` do u have any suggestion for me so it will return 2 ? – Nadav Aug 21 '10 at 20:48
I suspect you would not want to count leading spaces too " hello whats up" should return 2 as well right? I can propose 2 solutions. First is to trim all spaces before you start counting them . The second is to adjust the start and end point of your loop to the first and last non-space characters and then perform the count: int start=0;int end = strlen(pline); int i=0; while (pline[i++]==' ') start++; and the same way going down from the end of the string to adjust the "end". – spbfox Aug 21 '10 at 21:24

score 0 · Answer 2 · answered Aug 21 '10 at 20:24

0

Question: Blank char counter in C?

Answer: Yes.

answered Aug 21 '10 at 20:24

JustBoo

1,723
9
9

and yes the blank char is in c – Nadav Aug 21 '10 at 20:51

Blank char counter in C

2 Answers2