Question

The Key() function in php:

The key() function simply returns the key of the array element that’s currently being pointed to by the internal pointer. It does not move the pointer in any way. If the internal pointer points beyond the end of the elements list or the array is empty, key() returns NULL.

Is their any thing simmilar to that in AS3.0?

Also on a side note: does .= in php mean the same as +=?

Here is an example of what I am trying to achieve. Based on the above info for the PHP Key() function converted to actionscript 3.

Essentially in PHP this is what Key() is used for:

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
    if ($fruit_name == 'apple') {
        echo key($array).'<br />';
    }
    next($array);
}
?>

The above example will output:

fruit1
fruit4
fruit5

You can see more at: https://www.php.net/manual/en/function.key.php

Answer 1

Your example uses a php array as an hash map or a dictionary. The documentation says:

An array in PHP […] can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more.

There is a dedicated class for that in as3 and it is called Dictionary. You can also use an Array, or any other dynamic object to achieve the same functionality. But let’s use Dictionary here. The documentation says:

ActionScript 3.0 introduces an advanced type of associative array called a Dictionary …

Also, the functions current() and next() are somehow implementations of the iterator pattern, which has no built in equivalent in as3. But the closest thing to the code you provided is, I think, the use of a simple for..in loop:

for (var key:String in dictionary) {
    if (dictionary[key] == "apple")
        trace(key);
}