I want to use some PHP variables in my javascript. How do I do this?

• The PHP variable will be set only once on each page (so no worries about passing it back and forth!)
• The javascript is an external .js file
• I want to avoid document.write() if possible
• Ideally, I would like to pass the PHP variable to a javascript function (as an argument, I suppose), to avoid creating a global JS variable and polluting the namespace. But that's not terribly important.

I'll also need to do some cleanup on the variable, but let's not worry about that for now.

Well, I seem to have worked it out:



...but if anyone knows how to avoid declaring a global variable, let me know. That would be a nice coding-purity touch.

Well, as long as the Javascript is inline, you can do what you did where ever you want, the variable don't have to be global...


This may be obvious, but i can't think of anything smarter at the moment... or i misunderstood the question.... (most likely the latter).

Yeah I remember learning this trick with Rakuli

If you wanted, you could set up a factory function on your external js file


And if you already are declaring some variables inside of your external .js file, it's just a matter of adding a property when you write it out with Pph



So now you are using an object that is already in existence by creating another object on page load -- no namespace issues arising apart from those that are already present.

Oh this is beyond my brain Hehehe...

See, there's the clever answer I was looking for

Ooooh, this looks interesting. I might need some more guidance on this later, but first I should play with it and see what happens.



Except I'm not (I only declare local variables; when I need a global variable, which is rarely, I create a function instead). So how would I access this factory data without attaching it to a global variable?

By the way, is that a good idea? For example, I had a global variable that checks for IE:



...and I encapsulated it in a function instead (to get rid of the global):



...and then I test for if(ie()==1) instead of testing for if(ie).

No, the slowest thing to do in Javascript, meaning the largest drain on client side resources by Javascript, is a function call. Javascript is an OOP language but it is not so to the point that complete abstraction is possible -- or the best solution.

If your namespace only has one object thats properties are objects, this is okay. Speed on todays computers isn't a huge problem but why use extra resources if you don't have to? If you only need to run a function once, it's probably best not to declare it as a function and instead create an object with the settings. This will save you some bandwidth as well (it's usually shorter to compare against variables [ if (ie) ] than functions [ if (ie()) ]

Let me check whether I've understood this correctly:

• Instead of using LOTS of global variables, it's better to create one object and store the "variables" inside that.
• This object should have a distinctive name, to make namespace conflicts improbable (e.g. BadmintonBibleObject).
• This is a better solution than attempting "complete abstraction" by encapsulating everything in functions, because function calls are much, much slower.

Is that correct?

In a nutshell that is correct.

Point one I can't confirm any further than saying that having one global packed with properties and avoiding potential namespace conflicts would be a better choice. The second and third points are logical and correct respectively.

So that one global could also be something other than an object? Excuse my denseness; I'm picking up the terminology as I go (I'm pretty sketchy on what an object is, having never used one).

Thanks for all this advice; I always seem to learn something fundamentally new when you answer one of my threads. Beyond the expediency of solving an immediate problem, I also enjoy learning something new.

Well an object is just the 'whole'.. It can be made up of properties and methods.

The global would either be an object or an array of objects or array of variables -- the same principle really; storing all global data under one namespace.

An object in javascript is like an object in PHP or python except that in javascript there is are more ways to create them. $ in jQuery is just an object and it stores everything it needs, all functions and properties to do everything it does.

Gotcha. Thanks.

It's my own fault for never learning to program "properly"; I just picked stuff up as I went along. This is actually quite an efficient style of learning, but it does leave dangerous gaps in my knowledge.

Thankfully, you help me fill in the gaps.

LOL, no probelm.