Clarification of challenge question from Hatsy Rei

Question

What is the output of this code?
char a = 'a';
static_cast <int>(a)+1 //what does this mean?
cout <<a;

Ans:a

How did we get the output as 'a'?

Answer 1

*Star wars Dark Side music plays*

*Space capsule opens, gas everywhere, Darth Rei steps out*

Welcome to the Dark Side... !!!!

--- ---

char a = 'a';
static_cast <int>(a)+1;
cout <<a;

What static_cast does here, is to cast (a) to int ASCII value and return to where it is called. The catch here is that static_cast is not printed, and static_cast doesn't 'convert' what is stored in a variable - It simply casts them. So, in order to correctly cast character a to int and output it, the code should have been:

char a = 'a';
cout << static_cast <int>(a);

Adding 1 to the static_cast statement was just a trick. Some may think that char a would end up storing 'b', but no.

Answer 2

In case you wanted the output to be 'b'... There are a few ways to do it, but if you wanted to go for static_cast...

char a = 'a';
cout << static_cast<char>(static_cast<int>(a) + 1);

Answer 3

It's a modification of typing, on a line, all by itself:

a;

If you want to compare, try exactly that (stating a value) in Python interactive mode vs. running a program: What should the 'program runner' (immediate mode interpreter vs. runtime/compiler) do with a statement with no left-hand side?

Answer 4

Thanks for the clarification, Hatsy Rei! 🍪

Answer 5

Tyvm ☺

Answer 6

Go through a very good article on data type conversion at
http://www.cplusplus.com/doc/tutorial/typecasting/

Answer 7

Is it covered in the C++ tutorial here?

Thanks for the answer, luka! 👍

Answer 8

@Hatsy Exactly where I went wrong haha. I typed in 'b' as the answer and was very confused when it was wrong. Thanks for clearing it up

Edit: Can you give the syntax in case I wanted the output to be "b'

Answer 9

One thing I hoped someone would add here (maybe Ace, if he'd seen it):

test.cpp:6:21: warning: expression result unused [-Wunused-value]
static_cast <int>(a)+1; //what does this mean?
~~~~~~~~~~~~~~~~~~~~^~
1 warning generated.

SoloLearn and many online compilers have warnings OFF or...hidden/sometimes I see them (the -W shows which of mine fired).

Some compilers, in certain modes, will even OMIT lines (if inlined), causing weird bugs (if you intend to call while discarding the result).

Answer 10

looks like typical c++ sorcery to me