ZEND PHP 5 Certification STUDY GUIDE

178 ” Elements of Object-oriented Design
}
$this->array[$offset] = $value;
function offsetGet ($offset) {
return $this->array[$offset];
}
function offsetUnset ($offset) {
unset ($this->array[$offset]);
}
function offsetExists ($offset) {
return array_key_exists ($this->array, $offset);
}
}
$obj = new myArray();
$obj[1] = 2; // Works.
$obj[’a’] = 1; // Throws exception.
As you can see, this feature of SPL provides you with an enormous amount of control
over one of PHP’s most powerful (and most useful) data types. Used properly,
ArrayAccess is a great tool for building applications that encapsulate complex behaviours
in a data type that everyone is used to.
Simple Iteration
The Iterator interface is the simplest of the iterator family, providing simple iteration
over any single-dimension array. It looks like this:
interface Iterator {}
function current();
function next();
function rewind();
function key();
function valid();
}
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
You can see a simple implementation of the interface that allows iteration over a
private property containing a simple array: