Count characters without empty spaces

Question

I have to count the number of characters in a string, but when there is empty space it is counted as a character. How do I remove these empty spaces? Any tips?

Answer 1

Alternatively, you could use a function where the entire string was traversed and the isspace was used to restrict counting of blank characters:

#include <ctype.h>

using namespace std;

int contarCaracteres(const string& str)
{
    int contador = 0;
    for(int i = 0; i < str.size(); ++i) 
    {
        if (!isspace(str[i]))
            ++contador;
    }

    return contador;
}

Obs: the isspace considers that a character is blank in the following cases:

• ' '
• '\t'
• '\n'
• '\v'
• '\f'
• '\r'

Answer 2

If your goal is just to count the different elements of white space, you should take a look at the function std::count_if of the standard algorithm library ( <algorithm> ).

With this function it is possible to count how many elements of an interval obey a predicate. Therefore, just use as a predicate for std::count_if a function that returns true when the character is not a blank space and false when it is. For this purpose we can use the negation of the function std::isspace.

int main() {
    auto s = std::string{ "25 caracteres sem os espacos." };
    auto n = std::count_if( std::begin( s ), std::end( s ),
                            [](char c){ return !std::isspace( c ); } );

    std::cout << "String: \"" << s << "\"\n";
    std::cout << "Quantidade de caracteres: " << s.size( ) << "\n";
    std::cout << "Quantidade de caracteres nao brancos: " << n << std::endl;
    return 0;
}

Follow an example running from the proposed solution: http://ideone.com/Wwpl5I

Answer 3

To do this you can use the function std::erase.

#include <iostream>
#include <algorithm>

using namespace std;

int main()
{
    string str = "Stack Overflow em Portugues";
    str.erase(remove(str.begin(),str.end(),' '),str.end());
    cout << str << endl;
    cout << "Lenght  " << str.length() << endl;
    return 0;
}

The result will be: