name = $name; $this->children = $children; } } $taxonomy = new Taxonomy( "Animals", array( new Taxonomy( "Vertebrates", array( new Taxonomy( "Warm-blooded", array( new Taxonomy( "Mammals", null ), new Taxonomy( "Birds", null ) ) ), new Taxonomy( "Cold-blooded", array( new Taxonomy( "Fish", null ), new Taxonomy( "Reptiles", null ) ) ) ) ), new Taxonomy( "Invertebrates", array( new Taxonomy( "Arthropods", array( new Taxonomy( "Crustaceans", null ), new Taxonomy( "Insects", null ) ) ) ) ) ) ); ?> 'An Informal Taxonomy of the Animal Kingdom' $taxonomy->name children) ?> $children != null $children as $child $child->name output_children($child->children)