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.