php get array element by position instead of numeric key - php

Question

I have a script that sorts input taking into account parent-child relations and the given display-order of each. A simplified array could look like this (the actual array has sub-arrays for children as well)
$output = Array
(
[7] => first array
[3] => second array
[1] => last array
)
In which the keys are the correspondings id's of the input. Now I wish to pass through this array from top to bottom in a while loop. I am not using foreach because if it has children multiple elements should be processed together, and not come again in the next 'loop'.
function recursive_func($array){
while ($i<=count($array)){
if (isset($array[$i]['children'])){
?><div><?php
recursive_function($array[$i]['children']);
$i++;
recursive_function($array[$i]['children']);
$i++;
?></div><?php
}
else{
?><div>Something</div><?php
$i++;
}
}
}
Clearly $array[$i]['children'] aren't the children of the i'th element (by position), but of the key with value i.
How can I pass through this array in the order as in $output?

Answer 1

You can use array_keys to get the keys in sorted order, and iterate through those.
Or can also use array_values, then you can index sequentially. Just do it right at the start.
function recursivefunction( $array ) {
$array = array_values($array);
....
}
I'm not sure why one entry having children means the next does as well, but I'll assume foreach is problematic.

Answer 2

Since the $output keys are not in order, one way is to do the following:
First get all the array keys:
$keys=array_keys($output);
Next, you may call the recursive_func($keys,$output):
function recursive_func($keys,$output){
$size=count($keys);
$i=0;
while ($i<=$size){
if (isset($output[$i]['children'])){
?><div><?php
$a=$output[$i]['children'];
recursive_function(array_keys($a),$a);
$i++;
$a=$output[$i]['children'];
recursive_function(array_keys($a),$a);
$i++;
?></div><?php
}
else{
?><div>Something</div><?php
$i++;
}
}
}
Please note that it is better that you set the $size of the array outside of the loop for better performance

Answer 3

As Garr Godfrey suggested, you can solve this with array_keys() like so
function recursive_func($array){
$keys = array_keys($array);
for ($i=0; $i<count($keys); $i++) {
if (isset($array[ $keys[$i] ]['children'])) {
recursive_func($array[ $keys[$i] ]['children']);
$i++;
recursive_func($array[ $keys[$i] ]['children']);
} else {
//sth, no $i++ here!
}
}
}
Because I am using a for loop here, the $i++ inside the loop will make it possible for you to skip one element