c++ string r prefix code example
Example 1: string literals in c++
#include <iostream>
#include <string>
#include <stdlib.h>// using c standard library
int main()
{
"Caleb";//String literal is a series of characters between two double quotes
//It is a const char array and array is just a ptr to a begining of block of memory
//String literals are stored in read only section of memory
const char name[8] = "Rhe\0eno";// \0 is null termination character
std::cout << strlen(name) << std::endl;//c function for size of string ,output => 3 due to null terminating char \0
std::cout << name << std::endl;// output => Rhe because null termination char \0
const char* name1 = u8"Caleb";//1 byte per char
const wchar_t* name2 = L"Caleb";//is 2 or 4 bytes per character dependent on compile on windows it's usually 2bytes but on linux it is 4 bytes per char
const char16_t* name3 = u"Caleb";//2 byte per char
const char32_t* name4 = U"Caleb";//4 byte per char
using namespace std::string_literals;
// this name space give number of functions for convenience
//std::string name0 = "Caleb" + "hello";//error because can't add ptr to ptr
std::string name0 = "Caleb"s + "hello";//s is an operator that returns std::string this will work because now adding a ptr to actual string
//various versions of strings
std::wstring namee = L"Caleb"s + L"hello";//wide string: 2 or 4 bytes depend on compiler
std::u32string namee32 = U"Caleb"s + U"hello";//u 32 string :4 bytes per char
std::u16string namee16 = u"Caleb"s + u"hello";//u16 string :2bytes per char
std::string namee8 = u8"Caleb";//1 byte per character
const char* example = R"(Line1
Line 2
Line 3
Line 4
)";//R:Raw for writing on different lines it prints escape characters
std::cin.get();
};
Example 2: raw string in c++
#include <iostream>
int main() {
//Display in Multiline using escape character /n
const char* example2 = "Line1\n"
"Line2\n"
"Line3\n"
"Line4\n"
;
std::cout << example2 << std::endl;
std::cout << "===================================" << std::endl;
// display in multiline using Raw
const char* example = R"(Line1
Line2
Line3
Line4
)";//no need to use escape character /n
std::cout << example << std::endl;
std::cin.get();
}