illustrate
1. Implementing the interface of other iterator functions is equivalent to installing a shell on other iterators. There is only one method.
2. Aggregation iterators can be combined with many iterators to achieve more efficient iteration.
Example
class MainIterator implements Iterator
{
private $var = array();
public function __construct($array) //Constructor function, initialize object array {
if (is_array($array)) {
$this->var = $array;
}
}
public function rewind() {
echo "rewindingn";
reset($this->var); //Point the internal pointer of the array to the first element }
public function current() {
$var = current($this->var); // Return the current value in the array echo "current: $varn";
return $var;
}
public function key() {
$var = key($this->var); //Return the key name of the current unit pointed to by the internal pointer in the array echo "key: $varn";
return $var;
}
public function next() {
$var = next($this->var); //Return the value of the next unit pointed to by the internal pointer of the array echo "next: $varn";
return $var;
}
public function valid() {
return !is_null(key($this->var); //Determine whether the key of the current unit is empty }
}The above is an introduction to PHP aggregate iterators. I hope it will be helpful to everyone.