In what scenario would one need to use PHPs magic function toString()

Question

Why would a programmer need to use the function? How would the same results have been achieved in php 4?

Answer 1

Please see this question. If its available, its preferable to casting to achieve the same.

Answer 2

In any scenario where you want to control how an object behaves when used in a string context (used as a string), e.g.

class FullName
{
    protected $firstName;
    protected $middleNames = array();
    protected $lastName;

    // ... methods ...

    public function __toString()
    {
        return sprintf('%s %s %s', $this->firstName,
                                   implode(' ', $this->middleNames),
                                   $this->lastName);
    }
}

$fullname = new FullName('John', array('Jim', 'Jamie'), 'Jackson');
echo "Hello, my name is $fullname";

You cannot simulate this method in PHP4. In fact, you shouldn't even be using PHP4 anymore at all.