Understanding some arduino code

[camochase]

So im looking at some code that takes the data of a snes controller and displays what is being pressed in the debug. I have never used arduino so im just trying to understand it it says

if (ControllerData & SNES_B) {
Serial.print(" B");
}

what exactly does the & symbol do in the condition?

 

[ResleyZ]

It seems that Arduino uses either C+ or C++, in which case the & symbol shows where the address will be taken from. In this case it takes the ControllerData from SNES_B. It might be useful to read a little introduction to C++, since it is always helpful to understand the basics. Not sure though, so I may be wrong

 

[Foxi4]

You're not posting the definition of "ControllerData" or "SNES_B", but assuming it works anything like libnds, what it basically says is that "if there is controller input AND this input is B, print "B" via the serial bus". "&" is a Bitwise AND operator, what it does is that it takes two binary representations and performs an AND operation on them, such operations are commonplace on controllers to distinguish between buttons.

 

[camochase]

I do understand C but the problem was i couldnt see how it was a condition that would work with an if statement but foxi4's comment on how it helps distinguish between buttons helped alot and sorry for not posting what controller data and things are

 

[Foxi4]

understand C but the problem was i couldnt see how it was a condition that would work with an if statement but foxi4's comment on how it helps distinguish between buttons helped alot and sorry for not posting what controller data and things are

If you don't have a comparison operator in an if statement, the the compiler assumes that you mean if(statement is true?).

 

[PityOnU]

It seems that Arduino uses either C+ or C++, in which case the & symbol shows where the address will be taken from. In this case it takes the ControllerData from SNES_B. It might be useful to read a little introduction to C++, since it is always helpful to understand the basics. Not sure though, so I may be wrong

Arduino code is closer to Java, so... not even close.

Snaps for Foxi.

 

[megazig]

arduino code is c++ wrapped

http://arduino.cc/en/Reference/HomePage