PHP数组中，根据一个value值获取到它的key值

$array = array("test0","test1","test2");

$array1 = array("test0","test1","test2","test1");

$key = array_search("test1",$array);

$key1 = array_search("test1",$array1);

echo $key;

echo $key1;

输出都是1    

如果有重复的value输出第一个相匹配的key