counting words of a string

Question

As the title states, few things I must add to explain: " "/tab/","/"." are things that divide words in my situation, another note that there can be more the one space or dot coming one after the other

this is what I have

int countWords(char * str, int length){
       int counter = 0;

        for( int i = 0; i < length; i++){
            if(( str[i] == " ") || ( str[i] == ".") || ( str[i] == ",")){
                if(( str[i+1] != " ") || ( str[i+1] != ".") || (str[i+1] != ",")){
                    if(( str[i-1] != " ") || ( str[i-1] != ".") || (str[i-1] != ","))
                        counter++;
                }
            }
        }
        return counter;
    }

I get an error saying that I can not compare int and a pointer, I do understand where that is coming from, but how can I get it to actually work?

Note* I can't use string.h

It's a good thing you can't use `string.h`. But please use the `string` header. :) — Rakete1111, May 28 '17 at 13:31
@πάντα ῥεῖ so it doesn't count for spaces, what else should I do? — Ahmad Khateeb, May 28 '17 at 13:32
@AhmadKhateeb Use a character literal for comparison instead: `str[i] == ' '` — πάντα ῥεῖ, May 28 '17 at 13:33
I think you can get a good solution from this [question](https://stackoverflow.com/questions/9210528/split-string-with-delimiters-in-c) — horro, May 28 '17 at 13:35
Duplicate of [Warning comparison between pointer and integer](https://stackoverflow.com/questions/32510218/warning-comparison-between-pointer-and-integer) or [Reading string by char till end of line C/C++](https://stackoverflow.com/questions/23726724/reading-string-by-char-till-end-of-line-c-c) — Bernhard Barker, May 28 '17 at 15:41
when checking for a word separator, suggest also checking for `'` `;` `?` `:` and similar characters — user3629249, May 29 '17 at 18:06
These are not actually requested as the input can not contain these — Ahmad Khateeb, Jun 02 '17 at 13:57

Vlad from Moscow · Accepted Answer · 2017-05-28T14:07:22.807

In expressions like this

str[i] == " "
          ^^^

you are trying to compare an object of type char with a string literal that is implicitly converted to the type char *.

You have to use a character constant instead of the string literal

str[i] == ' '
          ^^^

The enclosing if statements do not make sense. For example for i equal to 0 the expression str[i-1] tries to access memory beyond the string.

The first parameter of the function should be declared with qualifier const.

The function can look the following way as it is shown in the demonstrative program.

#include <stdio.h>

size_t countWords( const char *s ) 
{
    size_t n = 0;

    for (size_t i = 0; s[i] != '\0'; )
    {
        while (s[i] == ' '  || 
               s[i] == '\t' || 
               s[i] == '.'  || 
               s[i] == ',') ++i;

        if (s[i] != '\0')
        {
            ++n;
            while ( s[i] != '\0' &&
                    ! ( s[i] == ' '  ||
                        s[i] == '\t' ||
                        s[i] == '.'  ||
                        s[i] == ',')) ++i;

        }
    }

    return n;
}

int main( void )
{
    char *s = "  Hello\t, World...";

    printf("%zu\n", countWords(s));
}

The program output is

Or the function's implementation can look like

size_t countWords(const char *s)
{
    size_t n = 0;

    while ( *s )
    {
        while (*s == ' '  ||
               *s == '\t' ||
               *s == '.'  ||
               *s == ',') ++s;

        if ( *s )
        {
            ++n;
            while ( *s &&
                    !( *s == ' '  ||
                       *s == '\t' ||
                       *s == '.'  ||
                       *s == ',' ) ) ++s;

        }
    }

    return n;
}

A more general approach of declaring the function is the following

size_t countWords( const char *s1, const char *s2 );

where the string s2 specifies a set of word separators.

@0andriy Ordinarily, I'd agree, but the question notes that no string functions are allowed to be used, whether they're from the standard headers or from implementation-specific headers. — , May 28 '17 at 16:18

Vishwajeet Vishu · Answer 2 · 2017-05-29T14:58:30.607

If you want to count word there is one fine example in K&R ANSI C. Try to write program like this.

#include <stdio.h>
#define IN  1    /* inside a word */
#define OUT 0    /* outside a word */
/* count lines, words, and characters in input */
main()
{
   int c, nl, nw, nc, state;
   state = OUT;
   nl = nw = nc = 0;
   while ((c = getchar()) != EOF)
 {
    ++nc;
    if (c == '\n')
        ++nl;
    if (c == ' ' || c == '\n' || c = '\t')
        state = OUT;
    else if (state == OUT) 
    {
        state = IN;
        ++nw;
     }
   }
printf("%d %d %d\n", nl, nw, nc);
}

Hope this helps. :) You can find the pdf of this book here.

counting words of a string

2 Answers2