accessing class properties that are arrays in HEREDOC

Question

There's two different syntaxes in the example below. One works and the other does not! Actually I would expect it to be the other way round. The second syntax looks quite crappy to me.

<?php
class Vodoo
{
    public $foo = array();

    public function __construct()
    {
        $this->foo = array('one' => 1, 'two' => 2, 'three' => 3);
    }

    public function getFoo()
    {
        $return = <<<HEREDOC
<p>$this->foo[one]</p>      // outputs: "Array[one]"
<p>{$this->foo['two']}</p>  // outputs correct: "2"

HEREDOC;
        return $return;
    }
}
$bar = new Vodoo;
echo $bar->getFoo();
?>

Is it ok to use these curly braces and quote the associative index inside the HEREDOC?

edit: The expression inside the curly braces has to be written the way it'd appear outside the string!

Answer 1

Yes, this is valid.

In heredocs and double quoted strings you can use the syntax {$...} where ... is any valid PHP expression following a $.

This is similar to the #{...} syntax in Ruby, for example.

There is an example of this in the docs: http://php.net/manual/en/language.types.string.php#example-71

See complex curly syntax