(PHP 5, PHP 7, PHP 8)

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

interface ArrayAccess {
/* 方法 */
public offsetExists(mixed $offset): bool
public offsetGet(mixed $offset): mixed
public offsetSet(mixed $offset, mixed $value): void
public offsetUnset(mixed $offset): void
}

示例 #1 基础用法

<?php
class Obj implements ArrayAccess {
public $container = [
"one" => 1,
"two" => 2,
"three" => 3,
];

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

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

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

public function offsetGet($offset): mixed {
return isset($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);
?>

以上示例的输出类似于：

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
        )

)

目录

• 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