Built in variable?

[Q_Q]

Hi, I recently start to learn C++ and I have a question. Please help.
While looking at pieces of codes to familiarize myself with C++, I
encounter these strange variables. I don't even know if they are
variables. I've tried to search on the internet and look through
several books for them, but couldn't find them anywhere. They are
%%
$$
$1
$2

I know $1 and $2 are kind of familiar (perl). But %% and $$ are
really strange to me.

Thank you for your help

 

[=?ISO-8859-1?Q?Erik_Wikstr=F6m?=]

Hi, I recently start to learn C++ and I have a question. Please help.
While looking at pieces of codes to familiarize myself with C++, I
encounter these strange variables. I don't even know if they are
variables. I've tried to search on the internet and look through
several books for them, but couldn't find them anywhere. They are
%%
$$
$1
$2

I know $1 and $2 are kind of familiar (perl). But %% and $$ are
really strange to me.

Where ever you found them it was not in C++, there are not built-in, or
predefined variables in C++.

 

[Daniel Kraft]

Hi, I recently start to learn C++ and I have a question. Please help.

Where ever you found them it was not in C++, there are not built-in, or
predefined variables in C++.

Looks a bit like yacc/bison. But as Erik said, nothing to do with C++

Cheers,
Daniel

 

[Q_Q]

Looks a bit like yacc/bison. But as Erik said, nothing to do with C++

Cheers,
Daniel

Hi Daniel, I found it. It was part of Flex.

Thanks,
Binh Pham