Strings.md

How Strings work in C++

Video

Char 1 byte of memory (let's forget about +1) UTF-8, let's not consider here UTF-16 (2^16 possibilities) Let's forget about encoding to simplify things

For C++ we are assume: 1 char occupies 1 byte Strings are a string of chars, duh =)

String are immutable, you can change and make it bigger. Strings finish with a '\0'

std::basic_string

std::string is basically std::basic_string<char>

Other templates

Type	Definition
std::string	std::basic_string<char>
std::wstring	std::basic_string<wchar_t>
std::u16string (C++11)	std::basic_string<char16_t>
std::u32string (C++11)	std::basic_string<char32_t>
std::pmr::string (C++17)	std::pmr::basic_string<char>
std::pmr::wstring (C++17)	std::pmr::basic_string<wchar_t>
std::pmr::u16string (C++17)	std::pmr::basic_string<char16_t>
std::pmr::u32string (C++17)	std::pmr::basic_string<char32_t>

#include <iostream>
#include <string>

int main()
{
    // This is an "emulation" of strings in cpp
    // Const is used because strings are immutable
    //const char* name = "Cherno";

    std::string name = "Dalton"; // "Dalton" is a const char*
    std::cout << name << std::endl;

    //std::string hi = "Hello" + " world!";  // Error
    std::string hi = std::string("Hello") + " world!";  // Error
    //name.size();

    // Find a substring
    if (name.find("on") != std::string::npos)	// npos is a illegal position
    {
        std::cout << "find the substring";
    }

    std::cin.get();
}

// we are passing here a copy (value) not reference, it's slow
void PrintString(std::string string)
{
    string += "h";
    std::cout << string << std::endl;
}

// with 'const' if promise to not modify the input parameter and passing by reference (&) it's faster
void PrintString(const std::string& string)
{
    std::cout << string << std::endl;
}