ArrayAccess(数组式访问)接口
(No version information available, might only be in SVN)
简介
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)
}
Example #1 Basic usage
<?php
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);
?>
以上例程的输出类似于:
bool(true)
int(2)
bool(false)
string(7) "A value"
obj Object
(
[container:obj:private] => Array
(
[one] => 1
[three] => 3
[two] => A value
[0] => Append 1
[1] => Append 2
[2] => Append 3
)
)
Table of Contents
◾ArrayAccess::offsetExists — 检查一个偏移位置是否存在
◾ArrayAccess::offsetGet — 获取一个偏移位置的值
◾ArrayAccess::offsetSet — 设置一个偏移位置的值
◾ArrayAccess::offsetUnset — 复位一个偏移位置的值
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