手册中数组最后一个元素的 $value 引用在 foreach 循环之后仍会保留的理解

数组最后一个元素的 $value 引用在 foreach 循环之后仍会保留。建议使用 unset() 来将其销毁。Note:foreach 不支持用“@”来抑制错误信息的能力。

代码如下

if(version_compare(PHP_VERSION,'5.3.0','<')) die('require PHP > 5.3.0 !');

$arrayName = array(

'0' => array(

'1' =>"houzi" ,

'2' =>"xiaogou"

) ,

'1' => array(

'2' =>"houzi" ,

'3' =>"xiaogou" )

);

var_dump($arrayName);

foreach ($arrayName as $key => &$value) {

$value[2]="xiugua";

}

echo "-----------------------------------------------------------";

var_dump($value);

echo "-----------------------------------------------------------";

var_dump($arrayName);

echo "-----------------------------------------------------------";

unset($value);

var_dump($arrayName);exit;

结果如下：

0 =>
array (size=2)
1 => string 'houzi' (length=5)
2 => string 'xiaogou' (length=7)
1 =>
array (size=2)
2 => string 'houzi' (length=5)
3 => string 'xiaogou' (length=7)

-----------------------------------------------------------

array (size=2)
2 => string 'xiugua' (length=6)
3 => string 'xiaogou' (length=7)

-----------------------------------------------------------

array (size=2)
0 =>
array (size=2)
1 => string 'houzi' (length=5)
2 => string 'xiugua' (length=6)
1 => &
array (size=2)
2 => string 'xiugua' (length=6)
3 => string 'xiaogou' (length=7)

-----------------------------------------------------------

array (size=2)
0 =>
array (size=2)
1 => string 'houzi' (length=5)
2 => string 'xiugua' (length=6)
1 =>
array (size=2)
2 => string 'xiugua' (length=6)
3 => string 'xiaogou' (length=7)