array_uintersect()

(PHP 5, PHP 7)

计算数组的交集，用回调函数比较数据

说明

array_uintersect(array $array1,array $array2[,array $...],callable$value_compare_func): array

array_uintersect()返回一个数组，该数组包含了所有在$array1中也同时出现在所有其它参数数组中的值。数据比较是用回调函数进行的。此比较是通过用户提供的回调函数来进行的。如果认为第一个参数小于，等于，或大于第二个参数时必须分别返回一个小于零，等于零，或大于零的整数。

参数

$array1

第一个数组。

$array2

第二个数组。

$value_compare_func

在第一个参数小于，等于或大于第二个参数时，该比较函数必须相应地返回一个小于，等于或大于 0 的整数。

callback(mixed $a,mixed $b): int

返回值

Returns an array containing all the values of$array1that are present in all the arguments.

范例

Example #1array_uintersect()例子

<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "GREEN", "B" => "brown", "yellow", "red");
print_r(array_uintersect($array1, $array2, "strcasecmp"));
?>

以上例程会输出：

Array
(
    [a] => green
    [b] => brown
    [0] => red
)

参见

• array_intersect() 计算数组的交集
• array_intersect_assoc() 带索引检查计算数组的交集
• array_uintersect_assoc() 带索引检查计算数组的交集，用回调函数比较数据
• array_uintersect_uassoc() 带索引检查计算数组的交集，用单独的回调函数比较数据和索引

I want to stress that in the user function, you do need to return either a 1 or a -1 properly; you cannot simply return 0 if the results are equal and 1 if they are not. 
The following code is incorrect:
<?php
function myfunction($v1,$v2) 
{
if ($v1===$v2)
  {
  return 0;
  }
return 1;
}
$a1=array(1, 2, 4);
$a2=array(1, 3, 4);
print_r(array_uintersect($a1,$a2,"myfunction"));
?>
This code is correct:
<?php
function myfunction($v1,$v2) 
{
if ($v1===$v2)
  {
  return 0;
  }
if ($v1 > $v2) return 1;
return -1;
}
$a1=array(1, 2, 4);
$a2=array(1, 3, 4);
print_r(array_uintersect($a1,$a2,"myfunction"));
?>

When trying to do a case insensitive comparison between arrays of words, the strcasecmp function works very nicely with this one like so: 
$arr1 = array('blue', 'green', 'red');
$arr2 = array('BLUE', 'Purple', 'Red');
$loose_matches = array_uintersect($arr1, $arr2, 'strcasecmp');
print_r($loose_matches) // array('blue', 'red');

As for the other "compare function" callbacks, the return value from the callback function doesn't need to be -1, 0, or 1.
cmp($a,$b) just needs to be <0, =0, or >0 depending on whether $a<$b, $a=$b, or $a>$b.