"PHP Predefined Interface" iterator

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Iterator (iterator) interface

Summary: An interface for an external iterator or class that can iterate internally.

Specific function explanation

Interface Summary:

Iterator extends Traversable {/    * method */    Abstract public mixed current (void) abstract public    scalar key (VO  ID) abstract public    void Next (void),    abstract public void rewind (void),    abstract public bool Valid (void )}

Example:

Example #1 Basic usage (the order in which iterator methods are called when using foreach) <?phpclass Myiterator implements Iterator {private $position = 0;      Private $array = Array ("Firstelement", "Secondelement", "lastelement",);    Public Function __construct () {$this->position = 0;        } function Rewind () {var_dump (__method__);    $this->position = 0;        } function current () {var_dump (__method__);    return $this->array[$this->position];        } function key () {var_dump (__method__);    return $this->position;        } function Next () {var_dump (__method__);    + + $this->position;        } function valid () {var_dump (__method__);    return Isset ($this->array[$this->position]);    }} $it = new Myiterator;foreach ($it as $key = = $value) {var_dump ($key, $value); echo "\ n";} 1.rewind, valid-------valid, Key3.next, valid, current, key 2.next, Gt Key4.Next-valid?> 

Iterator (iterator) interface

Summary: An interface for an external iterator or class that can iterate internally.

Specific function explanation

Interface Summary:

Iterator extends Traversable {/    * method */    Abstract public mixed current (void) abstract public    scalar key (VO  ID) abstract public    void Next (void),    abstract public void rewind (void),    abstract public bool Valid (void )}

Example:

Example #1 Basic usage (the order in which iterator methods are called when using foreach) <?phpclass Myiterator implements Iterator {private $position = 0;      Private $array = Array ("Firstelement", "Secondelement", "lastelement",);    Public Function __construct () {$this->position = 0;        } function Rewind () {var_dump (__method__);    $this->position = 0;        } function current () {var_dump (__method__);    return $this->array[$this->position];        } function key () {var_dump (__method__);    return $this->position;        } function Next () {var_dump (__method__);    + + $this->position;        } function valid () {var_dump (__method__);    return Isset ($this->array[$this->position]);    }} $it = new Myiterator;foreach ($it as $key = = $value) {var_dump ($key, $value); echo "\ n";} 1.rewind, valid-------valid, Key3.next, valid, current, key 2.next, Gt Key4.Next-valid?>