I’m new-ish to php, and need to play around with some things in the EE files. So I have a few questions regarding php.

1) Whats $$variable mean?
2) What’s the question mark for?
3) What’s the -> do?

Example:

  $r .= $DSP->input_checkbox($val, ‘y’, ($$val == ‘y’) ? 1 : ‘’).NBS.$LANG->line($val);

I know coding, I just don’t know php super well yet.

1. It’s a variable variable.
2. The so called ternary operator (if/else, basically)
3. Object oriented PHP. “DSP->input_checkbox” calls the function input_checkbox() of the class DSP. You might want to read up on it

3. More specifically, -> is an object operator used to access the members of an object.  To be correct, $DSP->input_checkbox() accesses the input_checkbox() method (or function if you prefer) of the object held in the variable $DSP, not the class DSP.  To directly access members of a class without creating an object, you’d use the Paamayim Nekudotayim operator, a.k.a the scope resolution operator, a.k.a the double colon, i.e. ClassName::methodName()