The challenge for this month’s Exercise is to write the charcount() function, which returns the number of characters in a string. The character matches exactly, so don’t worry about checking uppercase and lowercase differences.

My solution involves using a while loop to move a pointer through the string. An if comparison checks for the given character, tallying the result in variable total. Here is the full code, with my charcount() function up top:

2023_09-Exercise.c

#include <stdio.h>

int charcount(char *s,char c)
{
    int total = 0;

    while(*s)
    {
        if( *s==c )
            total++;
        s++;
    }

    return(total);
}

int main()
{
    const int size = 64;
    char buffer[size];
    char c,t;

    printf("Enter a string: ");
    fgets(buffer,size,stdin);
    printf("Enter a character to find: ");
    scanf("%c",&c);

    t = charcount(buffer,c);
    printf("There are %d letters '%c' in: %s",
            t,
            c,
            buffer
          );

    return(0);
}

Pointer s represents the string passed. The while loop processes the entire string: while(*s) with the s pointer address incremented within the loop: s++ It’s okay to modify this pointer variable within the charcount() function as this change doesn’t affect the pointer in the main() function.

Variable total is initialized to zero: int total = 0; It’s incremented only when a match is found inside the string. When no characters match, the preset value zero is returned.

Here is a sample run of my solution:

Enter a string: Peter Piper picked a peck of pickled peppers
Enter a character to find: p
There are 7 letters 'p' in: Peter Piper picked a peck of pickled peppers

I hope your solution met with success. Remember, mine isn’t the only approach to solving the problem.