Why can't I assign an array variable directly to another array variable with the '=' operator?

Question

Why does the following assignment not work? I would like a low-level explanation if possible. Also, here's the compiler error I get: incompatible types in assignment of 'char*' to 'char [20]'

class UCSDStudent {

  char name[20];

  public:

    UCSDStudent( char name[] ) {
      //this-> name = name; does not work! Please explain why not
      strcopy( this -> copy, copy ); //works 
    }

};

Answer 1

Because when you have a function call like this UCSDStudent( char name[] ) only the adress of the array name is copied instead of the whole array. It is a C\C++ feature.

Furthermore the name defined as char name [20] is not a modifiable lvalue.

Regarding strcpy: it will bring undefined behaivour as if your source array doesn't have a NULL character it will copy some trash to this->name too. You may read more about strcpy here

Answer 2

If you still want to assign array to array, use a loop.

for eg: class UCSDStudent {

char name[20];

public:

UCSDStudent( char name[] ) 
{

for(int i = 0; i<20; i++)
  {
  this-> name[i] = name[i];

  }
}
};