字符串的数组键始终计算为第一个字符（true）

Question

When:

$person = array('name' => 'bill');

isset($person['jibberish']) evaluates to FALSE.

But:

$person = 'bill';

isset($person['jibberish']) evaluates to TRUE, as $person['jibberish'] returns the first character of string $person.

Is this as intended? This came as a shocker to me today, as I've always used empty($array['key']) without ever including is_array() in my if statements.

Answer 1

Because $person is a string, the array-like-index is converted to an int.

(int)'any non-numeric string in the world' == 0

So, you "naturally" get the first character of any string if you use a random, non-numeric string as the index.