C++ character counter: count the characters in a string

1. All characters in a string

The basic way to count characters in C++ is the size() or length() method of the std::string class. They return the length of the string in bytes. In pure ASCII text the byte count equals the number of characters.

// All characters (in bytes)
#include <iostream>
#include <string>

int main() {
    std::string text;
    std::getline(std::cin, text);
    std::cout << "Characters: " << text.size() << "\n";
    return 0;
}

2. Characters without spaces

When you want to count only the actual characters, iterate over the string and skip whitespace with the std::isspace function. This gives you the equivalent of the page counter's no-spaces figure.

// Characters without spaces
#include <iostream>
#include <string>
#include <cctype>

int main() {
    std::string t; std::getline(std::cin, t);
    int n = 0;
    for (unsigned char c : t)
        if (!std::isspace(c)) n++;
    std::cout << "Without spaces: " << n << "\n";
    return 0;
}

3. Word count

Words are conveniently counted with a std::istringstream stream, which splits the text into words at the spaces.

// Word count
#include <iostream>
#include <sstream>
#include <string>

int main() {
    std::string line; std::getline(std::cin, line);
    std::istringstream iss(line);
    std::string word; int words = 0;
    while (iss >> word) words++;
    std::cout << "Words: " << words << "\n";
    return 0;
}

UTF-8: bytes are not the same as visible characters

This is the biggest pitfall with non-ASCII text. std::string::size() returns the byte count, not the number of visible characters. In UTF-8 encoding, letters like é, ñ and ö take two bytes and many emoji take as many as four. That is why the word "café" can look like five bytes even though it has four visible characters.