ArrayAccess接口
ArrayAccess接口是對象的行為看起來像個數組,定義了四個方法。接口概要如下:
ArrayAccess { /* Methods */ abstract public boolean offsetExists ( mixed $offset ) abstract public mixed offsetGet ( mixed $offset ) abstract public void offsetSet ( mixed $offset , mixed $value ) abstract public void offsetUnset ( mixed $offset ) }
ArrayAccess接口自身沒有提供計算書組重元素數量的功能,如果要計算數量可以通過實現Countble接口。這個接口包含了一個count()方法,並且返回元素的數量。
<?php class MyArray implements ArrayAccess { protected $_arr; public function __construct() { $this->_arr = array(); } public function offsetSet($offset, $value) { $this->_arr[$offset] = $value; } public function offsetGet($offset) { return $this->_arr[$offset]; } public function offsetExists($offset) { return array_key_exists($offset, $this->_arr); } public function offsetUnset($offset) { unset($this->_arr[$offset]); } } $MyArray = new MyArray(); $MyArray['first'] = 'test'; echo $MyArray['first']; unset($MyArray['first']); ?>
ArratObject 類介紹
ArrayObject 類是一個 ArrayAccess 接口的實現類,它提供了迭代功能,以及很多用來排序和處理數據的非常有用的方法。
ArrayObject implements IteratorAggregate , ArrayAccess , Serializable , Countable { /* Constants */ const integer STD_PROP_LIST = 1 ; const integer ARRAY_AS_PROPS = 2 ; /* Methods */ public __construct ([ mixed $input = [] [, int $flags = 0 [, string $iterator_class = "ArrayIterator" ]]] ) public void append ( mixed $value ) public void asort ( void ) public int count ( void ) public array exchangeArray ( mixed $input ) public array getArrayCopy ( void ) public int getFlags ( void ) public ArrayIterator getIterator ( void ) public string getIteratorClass ( void ) public void ksort ( void ) public void natcasesort ( void ) public void natsort ( void ) public bool offsetExists ( mixed $index ) public mixed offsetGet ( mixed $index ) public void offsetSet ( mixed $index , mixed $newval ) public void offsetUnset ( mixed $index ) public string serialize ( void ) public void setFlags ( int $flags ) public void setIteratorClass ( string $iterator_class ) public void uasort ( callable $cmp_function ) public void uksort ( callable $cmp_function ) public void unserialize ( string $serialized ) }