1 $arr1 = array('r' => 'red','u' => 'blue', 'g' => 'green', 'b' => 'black');
 2 $arr2 = array('r' => 'red', 'b' => 'blue');
 3 /***********array_intersect(计算数组同键值的交集)*****************/
 4 $arrIntersect = array_intersect($arr1, $arr2);
 5 var_dump($arrIntersect);//=>array(2) { ["r"]=> string(3) "red" ["u"]=> string(4) "blue" }
 6 
 7 /***********array_intersect_key(计算数组同键名的交集)*****************/
 8 $arrIntersectKey = array_intersect_key($arr1, $arr2);
 9 var_dump($arrIntersectKey);//=>array(2) { ["r"]=> string(3) "red" ["b"]=> string(5) "black" }
10 
11 /***********array_intersect_assoc(计算数组同键名同键值的交集)*****************/
12 $arrIntersectAssoc = array_intersect_assoc($arr1, $arr2);
13 var_dump($arrIntersectAssoc);//=>array(1) { ["r"]=> string(3) "red" }
14 
15 /***********array_intersect_uassoc(用自定义的回调函数来计算数组同键名同键值的交集)*****************/
16 $arrIntersectUassoc = array_intersect_uassoc($arr1, $arr2, 'arr_intersect_uassoc_func');
17 var_dump($arrIntersectUassoc);//=>array(1) { ["r"]=> string(3) "red" }
18 
19 function arr_intersect_uassoc_func($a, $b) {
20     if ($a === $b)
21         return 0;
22     elseif ($a > $b)
23         return 1;
24     else
25         return -1;
26 }
27 
28 /***********array_intersect_ukey(用自定义的回调函数来计算数组同键名的交集)*****************/
29 $arrIntersectUkey = array_intersect_ukey($arr1, $arr2, 'arr_intersect_ukey_func');
30 var_dump($arrIntersectUkey);//=>array(2) { ["r"]=> string(3) "red" ["b"]=> string(5) "black" }
31 
32 function arr_intersect_ukey_func($k1, $k2) {
33     if ($k1 == $k2)
34         return 0;
35     elseif ($k1 > $k2)
36         return 1;
37     else
38         return -1;
39 }