前面整理过一篇文章，描述php中的array与json的array和object的转换关系。http://www.cnblogs.com/x3d/p/php-json-array-object-type.html
在实际开发中，如何保障这种关系呢？一般来说，需要定义一些类型来做映射。
废话不多说，上码。
1. 最终用法
use hybrid\one\collection\JSONArray;
// json
$arr = new JSONArray();
//$arr[2] = 444; // 异常 不是从0开始
$arr[0] = 1;
$arr[1] = 2;
$arr[2] = 3;
var_dump($arr->__toArray());
$arr[6] = 66; // 异常 索引跳跃
$arr['91'] = 91; // 异常 不是整型
2. 相关基础类
<?php
namespace hybrid\one\collection;
use ArrayIterator;
use IteratorAggregate;
use ArrayAccess;
use Countable;
use hybrid\one\Collection;
/**
* PHP的数组结构灵活,但在输出JSON数据时往往造成混乱,针对JSON内置的数据集合类型映射对应的PHP类
* JSONArray的特征:
* 数据的下标:
* 必须是数字索引，
* 必须从0开始，
* 必须从小到大依次增加、中间不可以跳跃、顺序不可变动
*/
class JSONArray implements Collection, ArrayAccess, Countable, IteratorAggregate
{
/**
*
* @var array
*/
private $data;
public function __toArray(): array
{
return $this->data;
}
/**
* Returns an iterator for traversing the data.
* This method is required by the SPL interface [[\IteratorAggregate]].
* It will be implicitly called when you use `foreach` to traverse the collection.
* @return \ArrayIterator an iterator for traversing the cookies in the collection.
*/
public function getIterator()
{
return new ArrayIterator($this->data);
}
/**
* Returns the number of data items.
* This method is required by Countable interface.
* @return integer number of data elements.
*/
public function count()
{
return count($this->data);
}
/**
*
* @param mixed $offset
* @return boolean
*/
private function offsetLegal($offset)
{
return is_int($offset);
}
/**
* This method is required by the interface [[\ArrayAccess]].
* @param int $offset the offset to check on
* @return boolean
*/
public function offsetExists($offset)
{
if (!$this->offsetLegal($offset)) {
throw new IllegalOffsetException;
}
return isset($this->data[$offset]);
}
/**
* This method is required by the interface [[\ArrayAccess]].
* @param integer $offset the offset to retrieve element.
* @return mixed the element at the offset, null if no element is found at the offset
*/
public function offsetGet($offset)
{
if (!$this->offsetLegal($offset)) {
throw new IllegalOffsetException;
}
return isset($this->data[$offset]) ? $this->data[$offset] : null;
}
/**
* This method is required by the interface [[\ArrayAccess]].
* @param integer $offset the offset to set element
* @param mixed $item the element value
*/
public function offsetSet($offset, $item)
{
if (!$this->offsetLegal($offset)) {
throw new IllegalOffsetException;
}
if (!$this->offsetExists($offset) && ($offset > $this->count())) {
throw new IllegalOffsetException('offset value is illegal, must be ordered integer value or existed offset given');
}
$this->data[$offset] = $item;
}
/**
* This method is required by the interface [[\ArrayAccess]].
* @param mixed $offset the offset to unset element
*/
public function offsetUnset($offset)
{
if (!$this->offsetLegal($offset)) {
throw new IllegalOffsetException;
}
unset($this->data[$offset]);
}
}
3. 其它
JSONObject 类可以依葫芦画瓢。