Re: [PHP4BETA] Global variables inside a function?

Hi, Lars Torben Wilson wrote: > > Andreas Pour writes: > > Lars Torben Wilson wrote: > > > > > > Peter Kovacs writes: > > > > Is there an easy and efficient way to declare all the global variables to > > > > be global within a function? > > > > > > > > Peter > > > > > > > > -------------------------------------------------- > > > > Peter D. Kovacs KnowPost.com LLC > > > > Lead Engineer peter@knowpost.com > > > > -------------------------------------------------- > > > > > > In PHP4, this is simple: just put 'extract( $GLOBALS );' at the > > > beginning of the function definition: > > > > Unfortunately, this only gives you read, not write, access to the > > GLOBALS, and it's also not especially efficient. What would be nice is > > a way to modify the scoping rules to be more C/C++/etc.-like, maybe w/ a > > func like: > > > > set_var_scope("LOCAL_ONLY") // the default > > and > > set_var_scope("LOCAL_GLOBAL") > > > > > > Ciao, > > > > Andreas > > True. Although you can get read/write access to all globals, it's even > less efficient than the extract() option. The following is one way, > which could even be easily extended to allow you to manage a global > array of variable names to be included in the bulk globalization. That > would be even worse for efficiency, though, and the code would quickly > start looking really ugly. :) > > <?php > $booger = 'This is a test'; > > function foo() { > while ( list( $key, $val ) = each( $GLOBALS ) ) { > global $$key; > } > echo $booger; > } Yes, here function overhead becomes quite prohibitive :-). An easier way to have a "function" that accesses all GLOBALS is to put it by itself in a file and 'include()' it -- and also leave out the function declaration part ;-). > > foo(); > ?> > > Otherwise, the scoping rules aren't that hard to get used to. I politely disagree. I can't tell you how many times I've gotten "not defined" errors . . . . Guess I'm an old dog when it comes to scoping rules . . . . > On large > projects, it's nice to know that your locals are _always_ local unless > you specifically globalize them. I like the C++ approach the best -- if you throw a declaration in front of it it's always local, and nicely enough you can include the declaration in a statement. PHP also allows this, but only in class definitions . . . . So the parser should be able to handle this already. > It seems that being able to change > that would result in increased ambiguity, and possibly problems with > exchanging code with those whose existing code uses the opposite > setting. Hence my set_var_scope() suggestion -- this would operate on a per-function level. If it's set to LOCAL_GLOBAL, if a symbol is not found in the local symbol table, you just do a global lookup -- minimal code required, unless Zend does something I am not anticipating. > > There are many who do not believe that the C-style scoping rules are a > Good Thing, at least not for a higher-level language like PHP. Opinions, > of course, vary. :) That's why the configurable approach is so appealing :-). Ciao, Andreas