在PHP中获取2D数组的值

I have this array:

$array = array (
    "key1" => "Value 1",
    "key2" => "Value 2",
    "key3" => "Value 3",
    "key4" => "Value 4",
    ...
);

I am submitting a key with a form, so I want to assign a variable the value that belongs to that key, for example:

$key = $_POST['key'];
$value = ?????; //this is what I need

This might be very simple, but I haven't done it in a very long time and I have forgotten how to do it.

Thanks.

This should do the trick:

$value = $array[$key];

or without another variable:

$value = $array[$_POST['key']];

If you do receive a Notice: Undefined index ... you should check your array before you try to get the value with:

$value = array_key_exists($_POST['key'], $array) ? $array[$_POST['key']] : null;

This condition checks if the key exists. If so, it gets the value. If not, the value of $value will be null.