Doubt with cstring and string

The cstring library (also accessible via string.h ) is a library imported from C. Since C is not an object-oriented language, it is focused on working with char* fixes. Thus, we find functions such as:

• strcpy : Copy a text string
• strlen : Length of a text string
• strcat : Concatenates two text strings

The string library is typical of C ++. This library revolves around the class std::string that comes to be the natural substitute of char* . The advantages of using this class over char* are several:

• Do not worry about dynamic memory management
• It is not necessary to manage your own buffers (eg: char buffer[500] )
• No capacity limitations
• It is compatible with char* via function string.c_str()

The class% co_of%, simplifying a lot, what it does is encapsulate a pointer of type string and manage its life cycle. It allows writing code faster, more secure since, for example, it prevents it from being written outside the memory reserved for this purpose, and more readable.

An example of readability:

char* charFunc(const char* cadena1, int numero)
{
  size_t len = strlen(cadena1);
  len += log10(numero) + 1; // Número de dígitos del número
  len += 1; // Espacio para el caracter '
char* charFunc(const char* cadena1, int numero)
{
  size_t len = strlen(cadena1);
  len += log10(numero) + 1; // Número de dígitos del número
  len += 1; // Espacio para el caracter '%pre%'
  char* ptr = new char[](len);

  if( ptr )
    sprintf(ptr,"%s%d",cadena1,numero);

  return ptr;
}

std::string stringFunc(const std::string& cadena1, int numero)
{
  return cadena1 + std::to_string(numero);
} 

int main()
{
  // Versión char*
  char* cadena1 = charFunc("Una prueba",10);
  std::cout << cadena1 << '\n';
  delete[] cadena1;

  // Versión string
  std::string cadena2 = stringFunc("Una prueba",10);
  std::cout << cadena2 << '\n';
  // No necesita delete
}
'
  char* ptr = new char[](len);

  if( ptr )
    sprintf(ptr,"%s%d",cadena1,numero);

  return ptr;
}

std::string stringFunc(const std::string& cadena1, int numero)
{
  return cadena1 + std::to_string(numero);
} 

int main()
{
  // Versión char*
  char* cadena1 = charFunc("Una prueba",10);
  std::cout << cadena1 << '\n';
  delete[] cadena1;

  // Versión string
  std::string cadena2 = stringFunc("Una prueba",10);
  std::cout << cadena2 << '\n';
  // No necesita delete
}

The cstring header has functions to handle C-style strings, functions such as strlen and strcpy

The string header provides the std :: string class and related functions and operators.

Headers have similar names, but they are not really related beyond that. They cover separate tasks.