Question

jQuery lets me chain methods. I also remember seeing the same in PHP so I wrote this:

class cat {
 function meow() {
 echo "meow!";
 }

function purr() {
 echo "purr!";
 }
}

$kitty = new cat;

$kitty->meow()->purr();

I cannot get the chain to work. It generates a fatal error right after the meow.

Answer 1

To answer your cat example, your cat’s methods need to return $this, which is the current object instance. Then you can chain your methods:

class cat {
 function meow() {
  echo "meow!";
  return $this;
 }

 function purr() {
  echo "purr!";
  return $this;
 }
}

Now you can do:

$kitty = new cat;
$kitty->meow()->purr();

For a really helpful article on the topic, see here: http://www.talkphp.com/advanced-php-programming/1163-php5-method-chaining.html