Converting C expression to PB

BackupUser · Post by **BackupUser** » Fri Mar 07, 2003 9:17 pm

Restored from previous forum. Originally posted by Max..

bIDCmd = (VersionParams.bIDEDeviceMap >> i & 0x10) ? \				IDE_ATAPI_ID : IDE_ID_FUNCTION;

I'm having a hard time with this one. Structure is there, constants defined. >> i & 0x10 _seems_ to be clear (at least it looks like the parts where I used that works) but with "? \ ..." the pain starts...

Anywhere Santa's little helpers around?

Max.

BackupUser · Post by **BackupUser** » Fri Mar 07, 2003 9:32 pm

Restored from previous forum. Originally posted by plouf.

\ means that the line continues to the next line

expresion ? result1 : result2

is an operator which returns result1 if expression is true
otherwise returns result2

hope that helps

Christos

BackupUser · Post by **BackupUser** » Fri Mar 07, 2003 9:36 pm

Restored from previous forum. Originally posted by Max..

Code: Select all

bIDCmd = (VersionParams.bIDEDeviceMap >> i & 0x10) ? IDE_ATAPI_ID : IDE_ID_FUNCTION;

Yes, thanks, helps already.

Found that "? :" are conditional operators. But still I need some digging to understand that... or do you know?

Max.

Edit:

Found this now...

`?:'
The ternary operator. `A ? B : C' can be thought of as: if A
then B else C. A should be of an integral type.

at http://docs.freebsd.org/info/gdb/gdb.in ... ators.html

Getting closer...

PS: Actually you said that already. Sorry, too tired. :-/

BackupUser · Post by **BackupUser** » Sat Mar 08, 2003 12:41 am

Restored from previous forum. Originally posted by Kale.

This is called a conditional expression and used lots in C++ and hibrids (Javascript, etc...) basically you have an expression to evaluate then 2 statements which are executed weather the expression is true or false. As christos says, it usually like this:

var = (expression to evaluate) ? var is this if true : var is this if false;

and thats it

--Kale

In love with PureBasic!

BackupUser · Post by **BackupUser** » Sat Mar 08, 2003 7:38 am

Restored from previous forum. Originally posted by plouf.

Found that "? :" are conditional operators. But still I need some digging to understand that... or do you know?

i believe this code is as this PB (but its been some time since i have touch C so ...

)

If (VersionParams\bIDEDeviceMap >> i & 0x10)
bIDCmd = #IDE_ATAPI_ID
Else
bIDCmd = #IDE_ID_FUNCTION
endif

Christos

BackupUser · Post by **BackupUser** » Sat Mar 08, 2003 12:35 pm

Restored from previous forum. Originally posted by Max..

If (VersionParams\bIDEDeviceMap >> i & 0x10)
bIDCmd = #IDE_ATAPI_ID
Else
bIDCmd = #IDE_ID_FUNCTION
endif

Yes, beside changing 0x10 to 16 I used it that way and it seems to do. Sadly I will only really be sure once all is done.

As I said yesterdays, was way too tired to understand your posting in the first run though it contained anything needed. The second run was better; must have been the Vodka that helped.

Max.