Nigdzie nie napisali?? Zajrzyj panie Pyton (

) do manuala do dzialu "Stringi". Jest tam to bardzo ładnie opisane, podane na przykladach, tak wiesz,napisali jak dla poczatkujacych

ps: sorki, nie do Strings a do Arrays
http://docs.php.net/manual/en/language.types.array.phpCytat
// Notice: Use of undefined constant fruit - assumed 'fruit' in...
print $arr[fruit]; // apple
// This defines a constant to demonstrate what's going on. The value 'veggie'
// is assigned to a constant named fruit.
define('fruit', 'veggie');
// Notice the difference now
print $arr['fruit']; // apple
print $arr[fruit]; // carrot
// The following is okay, as it's inside a string. Constants are not looked for
// within strings, so no E_NOTICE occurs here
print "Hello $arr[fruit]"; // Hello apple
// With one exception: braces surrounding arrays within strings allows constants
// to be interpreted
print "Hello {$arr[fruit]}"; // Hello carrot
print "Hello {$arr['fruit']}"; // Hello apple