Why do strings behave like an array in PHP 5.3?

Question

I have this code:

$tierHosts['host'] = isset($host['name']) ? $host['name'] : $host;

It's working fine in PHP 5.5, but in PHP 5.3 the condition returns true while $host contains a string like pjba01. It returns the first letter of $tierHosts['host'], that is, p.

What's so wrong with my code?

Schindler

You can bypass this behaviour with (is_array($host) && isset($host["name"])). Always check against the type you need if it's not clear which type you'll received. For more details on the behaviour you described see Rizier123s answer. – Killam

If you are interested in some of the other things that can catch you off-guard in PHP, read this. eev.ee/blog/2012/04/09/php-a-fractal-of-bad-design – Pyromorphite

Why do strings behave like an array...? Because they are an array... – Cockshy

Answer 1

You can access strings like an array and prior PHP 5.4 offsets like your name were silently casted to 0, means you accessed the first character of that string:

character | p | j | b | a | 0 | 1 |
-----------------------------------
index     | 0 | 1 | 2 | 3 | 4 | 5 |

After 5.3 such offsets will throw a notice, as you can also read in the manual:

As of PHP 5.4 string offsets have to either be integers or integer-like strings, otherwise a warning will be thrown. Previously an offset like "foo" was silently cast to 0.

Mirella