Difference between “as $key => $value” and “as $value” in PHP foreach

Question

I have a database call and I\'m trying to figure out what the $key => $value does in a foreach loop.

The reason I ask is because both these

Answer 1

Let's say you have an associative array like this:

$a = array(
    "one" => 1,
    "two" => 2,
    "three" => 3,
    "seventeen" => array('x'=>123)
);

In the first iteration : $key="one" and $value=1.

Sometimes you need this key ,if you want only the value , you can avoid using it.

In the last iteration : $key='seventeen' and $value = array('x'=>123) so to get value of the first element in this array value, you need a key, x in this case: $value['x'] =123.