Counting words that start with Capital Letters C++ [Help] - c++

Question

Hey everyone I'm a newbie to C++ and could use some help.
I'm trying to code a program which counts only the words that start with Capital Letters.
int countLegalWords(char str[])
int counter = 0; // counts the legal words
for (int i = 0; i < MAXSIZE; i++)
{
if (str[i] >= 'A' && str[i] <= 'Z')
{
if (str[i + 1] >= 'a' && str[i + 1] <= 'z')
{
counter++;
}
else if (str[i] == ' ')
i++;
}
}
return counter;
Example:
Input:
I liKE Ice Cream H
Output:
4 words with capital letters at the beginning of the word.

Answer 1

There are several problems with your code
In C++, std::string is used for strings. Things like ´char*´ or ´char[]´ are not used in C++ They are used in C. But C and C++ are 2 different languages
You use a C-Style array (char str[]). In C++, C-Style arrays are not used
There is a magic constant MAXSIZE, which has nothing to do with the length of the string. If MAXSIZE is 100 but the your string is smaller, then you compare out of bounds values in the for loop. This is a severe bug.
You need to understand that C-style strings are 0-terminated. The last charcter is a '\0'. You must not operate past the terminating 0.
Your logic in detecting words and word begin is wrong. You check any character for uppercase and then the next for lowercase. But this can happen also within a word. See your sentence with "liKe" in it.
You do not want to switch to C++. You have written in the comment that you want to use strcmp and such, which is a C-function
If you would write comments and use meaningful variable names, then you would find all errors by yourself.
OK, that were the problems. Now a possible solution, using your programming style.
#include <iostream>
int countLegalWords(char myString[]) {
// Here we will store the number of words which start with a capital letter
int countOfLegalWords = 0;
// We will iterate over the complete string and check all characters
unsigned int indexInString = 0;
// Check all characters of the string until we hit the terminating 0
while (myString[indexInString] != '\0') {
// Search for the begin of a word. This is the first non-space character
while (myString[indexInString] == ' ')
++indexInString;
// OK, Now we found the begin of a word. Check, if the first character is upper case
if ((myString[indexInString] >= 'A') and (myString[indexInString] <= 'Z')) {
// Yes, uppercase, count up
++countOfLegalWords;
}
// Now search for the end of the word or for the end of the complete string
while ((myString[indexInString] != '\0') and (myString[indexInString] != ' '))
++indexInString;
}
// And return the count of legal words to ther calling program
return countOfLegalWords;
}
int main() {
char myString[] = "I liKE Ice Cream H";
std::cout << "\nCount of legal words: " << countLegalWords(myString) << '\n';
}
in C++ all this would be done with a one liner:
#include <iostream>
#include <string>
#include <iterator>
#include <regex>
// Regex for a word starting with a capital letter
const std::regex re{ R"(\b[A-Z]\w*)" };
// Main program
int main() {
std::string myString{ "I liKE Ice Cream H" };
std::cout << "\nCount of legal words: " << std::distance(std::sregex_token_iterator(myString.begin(), myString.end(),re), {}) << '\n';
}