不同版本的PHP语法错误

Question

I sometimes get values from an array like this: $var = array ('key1' => 'value1')['key1']; , so $var should be equal to value1

I run code like this in a server having PHP v5.4.16 , for example, explode ('-', $str)[0]; and it works fine. Now if I transfer this code to another server which uses PHP v5.3.10 I get an error (syntax error): syntax error, unexpected '[' ...

Is this because of the version? (I don't think so because the difference between versions is so small..), or some setting in the server? Can anyone enlighten me?

Answer 1

Yes, it depends on the version of PHP you are running. As PHP docs mentions

As of PHP 5.4 it is possible to array dereference the result of a function or method call directly. Before it was only possible using a temporary variable.

As of PHP 5.5 it is possible to array dereference an array literal.

In PHP 5.3 you would have to use

$exploded = explode('-', $str);
$first = $exploded[0];
// or
list($first,) = explode('-', $str);

In PHP 5.4 and later you can use

$first = explode('-', $str)[0];