?

<?php?
//去除值为"Cat"的元素?
$a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse");?
print_r($a);?
unset($a[array_search("Cat",$a)]);//array_search("Cat",$a)按元素值返回键名。去除后保持索引?
print_r($a);?
?>

查看array_search用法

显示结果

去除前：?
Array?
(?
[a] => Dog?
[b] => Cat?
[c] => Horse?
)

去除后：

Array?
(?
[a] => Dog?
[c] => Horse?
)?