String Literals

sonny

Anyone know if there is a difference in the following commands...

SEND_STRING someDevice, 'Hello World'

and

SEND_STRING someDevice, "'Hello World'"


Thanks

DHawthorne

As stated, none. However, if you need to mix ASCII characters with variables, decimal or hex values, you need the quotes, as in:

SEND_STRING someDevice, "'Hello ', StringVar, 13"

My habit is to always use the double quotes in any case.

GSLogic

The first 'HelloWorld' is a literal -ASCII

The second "HelloWorld'" is a pre-defined variable

The first command will work if it is all you want to send but if you want to add a variable with it, then you must use the " ". It's good practice to ALWAYS use the " " in all command like:

SEND_STRING someDevice, " 'Hello World' "

with VARIABLE:
SEND_STRING someDevice, " 'Hello World', someVAR"

Hope this helps!

sonny

Thanks for the replies...

I've seen documentation with the literal within single ticks by themselves, and with double quotes around the single ones. Didn't think there was a difference, just wasn't sure.

mediapilotinc

You will need to be a little carefull when dealing with variables in Netlinx as some may operate differently depending on the section of code you are in. Learned this the hard way. Here's a sample:

DEFINE_CONSTANT
CHAR EF_2280[] = 'F01'
CHAR PGM_VOLUME_UP[] = "EF_2280,'MACROX4'"

BUTTON_EVENT[dvTPANEL,51]
{
PUSH:
{
SEND STRING dvA_CONF,"PGM_VOLUME_UP"
}
}

it ended up sending "EF_2280,'MACROX4'" out of the RS-232 port.

Assigning CHAR PGM_VOLUME_UP[12] in the DEFINE_VARIABLE section instead, and then adding the statement PGM_VOLUME_UP = "EF_2280,'MACROX4'" in the DEFINE_START section fixed the issue and sent "F01MACROX4".
Have not researched further why this is the case, but I have become very careful with strings in the DEFINE_CONSTANT section.

sonny

DEFINE_CONSTANT
CHAR EF_2280[] = 'F01'
CHAR PGM_VOLUME_UP[] = "EF_2280,'MACROX4'"

just a guess, but the statement "EF_2280,'MACROX4'" is an executable statement that happens during runtime to dynamically build a string. Stuff that goes in the DEFINE_CONSTANT section gets resolved at compile time, and the compiler is treating this differently.