最近在补充学习php基础的时候看到了spl的介绍，学习了一下iterator和arrayAccess的使用，iterator主要是对象的迭代，一般可以用在容器里面，或者工厂模式里面，最常见的应用场景就是laravel的容器了，arrayAccess也是这样的，那么我们接下来就看下他们是怎么使用的吧。
iterator简易demo如下：
<?php
class TestIterator implements Iterator
{
private $arr = [];
private $key = 0;
public function __construct(array $arr)
{
$this->arr = $arr;
}
public function rewind()
{
echo __METHOD__.PHP_EOL;
$this->key = 0;
}
public function current()
{
echo __METHOD__.PHP_EOL;
return $this->arr[$this->key];
}
public function next()
{
echo __METHOD__.PHP_EOL;
++$this->key;
}
public function valid()
{
echo __METHOD__.PHP_EOL;
return isset($this->arr[$this->key]);
}
public function key()
{
return $this->key.PHP_EOL;
}
}
$test = new TestIterator(['apple','orange','banana']);
foreach ($test as $k => $v) {
var_dump($v);
}
//输出为：
TestIterator::rewind
TestIterator::valid
TestIterator::current
/Users/icarus/Code/php/itertaor.php:46:
string(5) "apple"
TestIterator::next
TestIterator::valid
TestIterator::current
/Users/icarus/Code/php/itertaor.php:46:
string(6) "orange"
TestIterator::next
TestIterator::valid
TestIterator::current
/Users/icarus/Code/php/itertaor.php:46:
string(6) "banana"
TestIterator::next
TestIterator::valid
ArrayAccess示例demo如下：
<?php
class TestArrayAccess implements ArrayAccess
{
private $arr = [];
public function __construct(Array $arr)
{
$this->arr = $arr;
}
public function offsetExists($offset)
{
echo __METHOD__ . PHP_EOL;
return isset($this->arr[$offset]);
}
public function offsetGet($offset)
{
echo __METHOD__.PHP_EOL;
return $this->arr[$offset];
}
public function offsetSet($offset, $value)
{
echo __METHOD__.PHP_EOL;
$this->arr[$offset] = $value;
}
public function offsetUnset($offset)
{
echo __METHOD__ .PHP_EOL;
unset($this->arr[$offset]);
}
}
$test = new TestArrayAccess(['person'=>'man','fruit'=>'apple']);
var_dump($test['person']);
var_dump($test['children']);
$test['hello'] ='world';
var_dump($test['hello']);
iteroatr是用来迭代用的，而arrayaccess主要是用来当作数组用的，组合起来更加强大，可以参考pimple项目。本文主要是用来记录和学习用的。