How are strings structured in C++?

In C++, strings can be represented in several ways:

C-style strings: This is an array of characters ending with a null character (\0). Data type char* or const char*.
```
char c_str[] = "Hello, world!"; // Array of characters ending with '\0'
const char* const_c_str = "Another string"; // Pointer to a string literal
```
- Require manual memory management (e.g., when copying or concatenating).
- Less safe (possible buffer overflows).
- Use functions from <cstring> (e.g., strcpy, strlen, strcat).
std::string: A dynamically managed container class from the C++ standard library (<string>).
```
#include <string>

std::string cpp_str = "Hello, C++!";
cpp_str += " More text."; // Concatenation
size_t len = cpp_str.length(); // Get length
```
- Manages memory automatically.
- Safer and more convenient to use.
- Provides a wide range of methods for string manipulation (search, replace, insert, etc.).
- Can store arbitrary byte sequences, not just UTF-8 or ASCII.
Unicode-supporting strings: For working with wide characters and Unicode, use:
- wchar_t: Type for wide characters. Strings are represented as arrays of wchar_t*. Functions in <cwchar>.
- std::wstring: Similar to std::string, but works with wchar_t.
- C++11 and newer: char16_t, char32_t and corresponding std::u16string, std::u32string for UTF-16 and UTF-32.
```
#include <string>
#include <cwchar>

const wchar_t* w_c_str = L"Широкая строка"; // String literal with L prefix
std::wstring wide_str = L"Еще шире";
```

Comparison of char* and std::string:

Characteristic	`char*` (C-style)	`std::string`
Memory management	Manual (requires `malloc`, `free`, `strcpy`, `strcat`, etc.)	Automatic
Safety	Low (buffer overflows possible)	High
Ease of use	Low	High
Functionality	Limited (from `<cstring>`)	Rich set of methods
Efficiency	May be higher in simple cases (no class overhead)	Class overhead, but optimized
Data type	Array of `char` ending with `\0`	Wrapper class over dynamic array of characters