PHP ArrayAccess（数组式访问）接口-PHP预定义接口的使用-编程文章分享

PHP ArrayAccess（数组式访问）接口提供像访问数组一样访问对象的能力的接口

接口摘要：

ArrayAccess {

/* 方法 */

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 )

}

提供像访问数组一样访问对象的能力的接口

class obj implements arrayaccess {

    private $container = array();
    public function __construct () {
        $this -> container = array(
            "one"  => 1 ,
            "two"  => 2 ,
            "three" => 3 ,
        );
    }

    public function offsetSet ( $offset , $value ) {
        if ( is_null ( $offset )) {
            $this -> container [] = $value ;
        } else {
            $this -> container [ $offset ] = $value ;
        }
    }

    public function offsetExists ( $offset ) {
        return isset( $this -> container [ $offset ]);
    }

    public function offsetUnset ( $offset ) {
        unset( $this -> container [ $offset ]);
    }

    public function offsetGet ( $offset ) {
        return isset( $this -> container [ $offset ]) ? $this -> container [ $offset ] : null ;
    }
}



$obj = new obj ;
var_dump (isset( $obj [ "two" ]));
var_dump ( $obj [ "two" ]);
unset( $obj [ "two" ]);
var_dump (isset( $obj [ "two" ]));
$obj [ "two" ] = "A value" ;
var_dump ( $obj [ "two" ]);
$obj [] = 'Append 1' ;
$obj [] = 'Append 2' ;
$obj [] = 'Append 3' ;
print_r ( $obj );

PHP历史版本

PHP ArrayAccess（数组式访问）接口

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