php array key issue with foreach loop and multi-dim arrays - php

Question

I have listed an example below. What I need is for $key to return the actual index number (position) in the array during the loop, but instead it is returning Array. The same code works fine when given a single dimension array, but not in the example below.
GIVEN:
$screenshots would be similar to the following with only more entries.
Array
(
[0] => Array
(
[screenshot_id] => 871
[image_filename] => DSCF0124.JPG
)
)
PHP:
//build in clause & binding using selected array from above
$prefix = $in_clause = '';
$binding_clause = array();
foreach($screenshots as $key)
{
$in_clause .= $prefix.':selected_'.$key;
$prefix = ', ';
$binding_clause[':selected_'.$key] = $key['screenshot_id'];
}
RESULT:
$inclause = :selected_Array
$binding_clause =
Array
(
[:selected_Array] => 871
)
EXPECTED:
$inclause = :selected_0
$binding_clause =
Array
(
[:selected_0] => 871
)

Answer 1

Just because you call it $key doesn't make it a key. You need the key and the value (inner array):
foreach($screenshots as $key => $value)
{
$in_clause .= $prefix.':selected_'.$key;
$prefix = ', ';
$binding_clause[':selected_'.$key] = $value['screenshot_id'];
}

Answer 2

You need to tell it that you want the KEY and the VALUE.
like this:
foreach($screenshots as $key=>$screenShot)
That will get you the key and the value.

Answer 3

You just need to change your foreach to cast keys and values
foreach($screenshots as $key => $val)
Now the key is in your $key variable while you can access elements with $val array, for example $key['screenshot_id']
You can have a check to documentation examples here

Answer 4

Try:
foreach($screenshots as $key => $screenshot)
{
$in_clause .= $prefix.':selected_'.$key;
$prefix = ', ';
$binding_clause[':selected_'.$key] = $screenshot['screenshot_id'];
}
Read more about PHP foreach: http://php.net/manual/en/control-structures.foreach.php