Associative array single quote reference?

[thtmal]

associative array examples that I found on http://www.webcheatsheet.com/php/arrays.php

part of the 1st example(echo each associative array separately):
echo $second_array['key4'];

part of the 2nd example(echo by combining strings and each associative array):
echo "rose costs $flower_shop[rose], daisy costs $flower_shop[daisy], and orchid costs $flower_shop[orchid].";

I'm using PHP 5.2.5. The 1st example shows to echo each associative array separately, must use the single quote ['key1'], but with the 2nd example, the single quote causes an error if used, and must be removed. Does this have to do with the different versions of PHP, or is this the way PHP always worked. Because from the a few of the negative articles that I've read about PHP, is that it is a sloppy language(I'm not putting it down personally, it's just what I've read), and if that's just the way PHP worked as always, then I'm just starting to see maybe why. I used to program in VB, and do not recall the VB language being like this, in terms of using the syntax in an inconsistent way. Just curious

[NogDog]

Yep, an unfortunate "feature" of PHP is that an unquoted string used as an array key will be considered a constant, and if that constant has not yet been [man]define/mand, then it will be "self-defined" as having a value equivalent to its name, and a notice-level warning will be raised. However, to confuse things further, an associative array being interpolated within a double-quoted or [man]heredoc[/man] string must not have the key quoted, unless you use the "complex" variable notation (curly braces), in which case it should be quoted again as if it were not within a quoted string. :rolleyes:

So, the following are all valid:

$foo['bar'] = 'test';
echo "This is a $foo[bar].";
echo "This is a {$foo['bar']}.";
echo "This is a " . $foo['bar'] . ".";
// heredoc method:
echo <<<END
This is a $foo[bar].
This is another {$foo["bar"]}.
END;

printf("This is a %s.", $foo['bar']);

This will result in a parse error:

echo "This is a $foo['bar'].";

This will throw the "undefined constant" notice:

echo "This is a " . $foo[bar] . ".";