* Member initialization table format:
Constructor name (parameter table): a member name (initial value) in the class, a member name (initial value), ... {function body};
※ Prevent this parameter from misurbing parameter variables:
Return value type function name (const parameter, const parameter, ...);
※ Prevent all variables in the object of the object of this function:
Return value type function name (parameter table) Const;
※ Prevent other functions from writing to return the address or reference:
Const Return Value Type Function Name (Parameter Table);
* Copy constructor (automatically calls when using an object to initialize another object)
Features: With the same name, do not specify back; only 1 parameter is a reference to the class object.
Format:
Class demo {
PUBLIC:
Demo (const char * s) {...}; // constructor
Demo (Const Demo & St) {...}; // Copy constructor
Demo () {...}; // does not automate
~ Demo () {...} // destructor
}
...
Demo H ("first");
Demo r = h; // copy all members of the object H to the object R
/ / If you write a Demo R; r = h; no copy constructor is called
※ If you don't want to write a copy constructor and assignment function, it is not allowed to use the default function generated by the compiler. You can declare the copy constructor and assignment function as a private function, and you can write code. Such as:
Class A
{...
Private:
A (Const A & a); // Private copy constructor
A & OPERATE = (const A & a); // Private assignment function
}
If you write as follows:
A b (a); // Call private copy constructor
B = a; // Call the private assignment function
The compiler will point out errors because the outside world cannot operate A private function.
* Friends function
Putting with Friend before the member function name, it is a non-member function that can access the private member, which is the same as the normal function in definition and call.
