const char*

[nofish]

Hello, new member here currently learning C++ in self study.
I have the following code:

  const char * pchar = "123456789";
  cout << pchar << "/n"; // output: 123456789
  cout << pchar + 1 << "\n"; // output: 23456789, move pointer
  cout << *pchar << "\n"; // output: 1, deref. pointer
  cout << (*pchar) + 1 << "\n"; // output: 50 ??? 

Everything is clear to me (I think), but I don't understand the output of the last cout statement. Could someone explain ?
Thanks.

[MiiNiPaa]

Value of *pchar ('1') got promoted to int (49 in ASCII code) and then 1 added. Result of expression is int.

[nofish]

Thanks.
It's not fully clear to me yet.

I figured when I want to get what I actually expected ('2') I need to do an explicit cast like

cout << char((*pchar) + 1) << "\n"; // output: 2 

But I don't understand why the promotion is happening in the first place.
Could you elaborate ?

[MiiNiPaa]

You are adding two types which are not directly compatible: char + int. Smaller one is converted to larger one: (char→int) + int. Result is a common type: int.

Just to warn you about second quirk: any integral type smaller than int is pomoted to int in any operation. So char + short result is int, as both operands promoted to int. That is what happened in your case, actually.

[Dmytro]

Дякую!

Дійсно дивно!

Незрозуміло std :: cout << * pchar << "\ n"; // Output: 1, deref. pointer

Як це 1 чекаючи на зразок A34DFD45

Взагалі незрозуміло чого 50 ??
Thanks!

Really amazing!

It is not clear std :: cout << * pchar << "\ n"; // Output: 1, deref. pointer

As it is expecting one like A34DFD45

In general, it is not clear what 50 ??

[nofish]

Ah so we're talking about Implicit conversions like mentioned here ?

http://en.cppreference.com/w/cpp/language/implicit_cast

That's a topic new to me, have to read up on it.

If that's it, clear in principle now what's happening, so I''ll mark it as solved.

Thanks again.

[MiiNiPaa]

Yes, those are implicit conversions. They are everywhere. It is realy hard to write codewithout using at least some of them.

[nofish]

Got it, thanks.

[Dmytro]

мабудь неможна разименувати *pchar.
Чому неможна я навіть гадки не маю. Але результат у мене такий же самий.

rightly so can not dereferenced
* pchar.
Why can not I even have no idea. But the result I have this same.

[Dmytro]

- pchar 0x00417838 "123456789" const char *
49 '1' const char