running for loop on array without incremental index - php

Question

I have this arbitrary multi dimensional array.
Array (
[0] => Array
(
[0] => 0
[1] => 1
[2] => 2
)
[5] => Array
(
[0] => 0
[1] => 1
[2] => 2
)
[10] => Array
(
[0] => 0
[1] => 1
[2] => 2
)
[15] => Array
(
[0] => 0
[1] => 1
[2] => 2
)
[1] => Array
(
[0] => 2
[1] => 1
[2] => 2
)
[2] => Array
(
[0] => 2
[1] => 1
[2] => 2
)
)
I wanna run a for loop to extract the data of each subarray.
But I cannot do a simple for loop because the index (0,5,10,15,1) is arbitrary.
Is there a way to run a for loop then skip the sub array if it is empty?
Thanks!

Answer 1

This will take $array and loop though it, echoing the keys.
You have an array in an array, you can place a foreach in a foreach:
// First we take the main array ($array) and loop though its values
foreach( $array as $main_key =>$sub_array){
echo $main_key.": <br />\n"; // echo the key, some extra html to format
// the values of the mainarray are arrays themselves, just loop again:
foreach($subarray as $sub_key =>$subvalue){
echo '- '.$subvalue."<br />\n";
}
}
There's a bit of a trap here if you foreach in a foreach:
foreach($array as $key =>$value){
foreach($value as $key=>$value){ /* ... */; }
}
This will create very weird results. The inner foreach uses the same parameter-names and will mess everything up.