How do I pass a php variable in an array to javascript?

Question

I'm trying to pass a PHP variable to Javascript like this..

var url = <?php echo $urlArray[0]; ?>;

The contents of $urlArray[0] is a string from a json decoded array

"baby"

When I run the code I get the error..

Uncaught ReferenceError: baby is not defined

Answer 1

var url = "<?php echo $urlArray[0]; ?>";

you forgot the quotes.

If you need to export more complicated data structure, you may need json_encode. This might be helpful if exporting arrays and/or objects.

• Saturnix: you don't even know how many times I've forgot to use " in the dialogue between PHP and JS. I think switching to json encode will remove the need of quotes. Also that can lead to HUGE improvement: f.e. you can export arrays and arrays of object. You can set a defined data structure (agreed in both php and js), send it back and forth between the two and have your structure instantly recognized. If you're into js/php dialogue, you should really try to export some array of objects into js to see what I'm talking about.
• David Folksman: Thanks I marked the answer correct. I'll have a play about and see what you mean! :)
• Sam Dufel: PHP won't put it there for you - that is incorrect. If you're json_encoding a string, it will be automatically quoted.

Answer 2

json_encode is your friend - use to wrap anything you're trying to pass to javascript.

http://php.net/manual/en/function.json-encode.php

var url = <?php echo json_encode($urlArray[0]); ?>;

• David Folksman: Sorry, i'm a bit new to this.. why would I want to re-encode it, after I just decoded it?
• Sam Dufel: Variables echoed into javascript need to be properly escaped. There are a number of things in strings which can wreak havoc with your javascript if they are echoed directly. json_encode() will return a value which can be safely output to your javascript.