Polyglot array_extend() function for Javascript and PHP

Question

This is a polyglot function I've made out of fun.

The goal is to grab n arrays (or Javascript Objects) and 'extend' them in order to obtain a single array with all the values.

This function runs both in Javascript and PHP.

Please, try to ignore some kludges on my code.

Here is my 'art':

function array_extend() {
 //Detects if we are running in Javascript or PHP
 //In PHP, this will be false because PHP only parses
 //escape sequences in double-quoted strings (except the sequence \')
 $javascript = '0円' == "0円";
 //PHP arrays support 'key=>value' pairs, JS arrays don't.
 $result = $javascript ? new Object() : array();
 $arguments = $javascript? arguments : func_get_args();
 $get_keys = function($elem){
 if('0円' == "0円")//PHP complains if I use the var $javascript
 {
 $object = Object;
 return $object['keys']($elem); //PHP doesn't like the Object.keys syntax
 }
 else
 {
 return array_keys($elem);
 }
 };
 for($j = 0, $length_args = $javascript? $arguments['length']: count($arguments); $j < $length_args; $j++)
 {
 $keys = $get_keys( $arguments[$j] );
 for($i = 0, $length_keys = $javascript? $keys['length']: count($keys); $i < $length_keys; $i++)
 {
 $result[$keys[$i]] = $arguments[$j][$keys[$i]];
 }
 }
 return $result;
}

Example of usage:

array_extend([1,2,3,4,5],[9,8,7,6,5,4,3,2,1,0]);
//should return the last elements in the array:
array_extend({'a':1, 'b':2, 'c':3},{test:'nice'});
//Javascript: returns {'a':1, 'b':2, 'c':3, test:'nice'}
array_extend(array('a'=>1, 'b'=>2, 'c'=>3), array('test'=>'nice'));
//PHP: returns array('a'=>1, 'b'=>2, 'c'=>3, 'test'=>'nice')

What do you guys think?

What can I improve? Where should I have done something better?

• jsanc623: Wait....so you made a function that compiles to both PHP AND Javascript???
• Ismael Miguel: @jsanc623 Yes, that's exactly it. You can fire up your console, paste it and use it OR you can slap it in a PHP file and run this bad boy!
• jsanc623: Wh...why?? What are you trying to build? Please tell me this is just a learning exercise...
• Ismael Miguel: @jsanc623 I was bored and simply made this. No, it isn't an exercise. I really just made this out of fun. I saw a question on stackoverflow to do something similar (it wasn't asking a polyglot) and did this. To be honest, I enjoy making this kind of stuff.
• Ismael Miguel: @jsanc623 I don't see much that I can improve. I could use better scoping (since this function is 'leaking' into the window object). But the var keyword isn't allowed outside classes, in PHP. If there was a way to make a single local variable with Javascript in a non-obstructive way that works for both languages, I would use it. But that's it.

Answer 1

You may want to replace object key access notation with dot notation.

For example, instead of the following.

$object['keys']($elem);

Write this.

Object.keys($elem);

This works, because Object is interpreted as a constant, dot as concatenation, and keys($elem) as function call. Use of undefined constant doesn't warn if the code with it is not executed. Unknown functions don't error if they aren't called.

• Ismael Miguel: For some reason it failed to me. A LOT! That's why I used that weird kludge. But it worked now and it's worth noticing. Also, you can add there that I forgot the order of the variables. $i should be in the first loop and $j should be in the 2nd. If you find a way to make a local variable for Javascript without the keyword var (sounds insane, I know), I would thank you a lot!