数组的unset函数测试：
<?php
$removed = false;
$ay=['h1'=>'1233','h2'=>'1234','h3'=>'12344','h4'=>'11111'];
foreach ($ay as $i => $event) {
if ($event === '1234') {
unset($ay[$i]);
$removed = true;
}
}
print_r($ay);
结果是：
Array
(
[h1] => 1233
[h3] => 12344
[h4] => 11111
)
可见，key也消失了
对象的unset测试
class Test{
public $v;
}
$test=new Test();
$test->v="nihao";
$test->k="hi";
print_r($test);
unset($test->v);
print_r($test);
Test Object
(
[v] => nihao
[k] => hi
)
Test Object
(
[k] => hi
)
属性也消失了
