array_intersect_ukey()

(PHP 5 >= 5.1.0, PHP 7)

用回调函数比较键名来计算数组的交集

说明

array_intersect_ukey(array $array1,array $array2[,array $...],callable$key_compare_func): array

array_intersect_ukey()返回一个数组，该数组包含了所有出现在$array1中并同时出现在所有其它参数数组中的键名的值。

参数

$array1

Initial array for comparison of the arrays.

$array2

First array to compare keys against.

Variable list of array arguments to compare keys against.

$key_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 the values of$array1whose keys exist in all the arguments.

范例

Example #1array_intersect_ukey()例子

<?php
function key_compare_func($key1, $key2)
{
    if ($key1 == $key2)
        return 0;
    else if ($key1 > $key2)
        return 1;
    else
        return -1;
}
$array1 = array('blue'  => 1, 'red'  => 2, 'green'  => 3, 'purple' => 4);
$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan'   => 8);
var_dump(array_intersect_ukey($array1, $array2, 'key_compare_func'));
?>

以上例程会输出：

array(2) {
  ["blue"]=>
  int(1)
  ["green"]=>
  int(3)
}

上例中可以看到只有'blue'和'green'两个键名出现在两个数组中，因此被返回。此外注意'blue'和'green'的值在两个数组中是不同的。但因为只检查键名，因此还是匹配。返回的值只是$array1中的。

参见

• array_diff() 计算数组的差集
• array_udiff() 用回调函数比较数据来计算数组的差集
• array_diff_assoc() 带索引检查计算数组的差集
• array_diff_uassoc() 用用户提供的回调函数做索引检查来计算数组的差集
• array_udiff_assoc() 带索引检查计算数组的差集，用回调函数比较数据
• array_udiff_uassoc() 带索引检查计算数组的差集，用回调函数比较数据和索引
• array_diff_key() 使用键名比较计算数组的差集
• array_diff_ukey() 用回调函数对键名比较计算数组的差集
• 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_intersect_uassoc() 带索引检查计算数组的交集，用回调函数比较索引
• array_intersect_key() 使用键名比较计算数组的交集

"array_intersect_ukey" will not work if $key_compare_func is using regular expression to perform comparison. "_array_intersect_ukey" fully implements the "array_intersect_ukey" interface and handles properly boolean comparison. However, the native implementation should be preferred for efficiency reasons.
<?php
$key_compare_func = function ($a, $b) {
  var_dump('a=' . $a. '; b=' . $b);
  
  if (strpos($b, '/') === 0) {
    return preg_match($b, $a) > 0 ? 0 : -1;
  }
  
  if ($a == $b) {
    $weight = 0;
  } else if ($a > $b) {
    $weight = 1;
  } else {
    $weight = -1;
  }
  
  var_dump('literal comparison: ' . $weight);
  
  return $weight;
};
$foo = ['aab' => '', 'bbb' => '', 'ccb' => '', 'abb' => ''];
$bar = ['/[a-z]b[a-z]/' => ''];
$buz = ['/c[a-z][a-z]/' => ''];
echo PHP_EOL . 'array_intersect_ukey' . PHP_EOL . PHP_EOL;
$subject = array_intersect_ukey ($foo, $bar, $buz, $key_compare_func);
echo PHP_EOL;
var_dump($subject);
echo PHP_EOL . '_array_intersect_ukey' . PHP_EOL . PHP_EOL;
$subject = _array_intersect_ukey($foo, $bar, $buz, $key_compare_func);
echo PHP_EOL;
var_dump($subject);
/**
 * @author Gajus Kuizinas <gk@anuary.com>
 * @version 1.0.0 (2013 09 30)
 * @url https://gist.github.com/gajus/271ad5f36337a32a184c
 */
function _array_intersect_ukey (array $arr1, array $arr2, $key_compare_func) {
  $arr_matched = [];
  $arr_unmatched = [];
  
  $args = func_get_args();
  
  $key_compare_func = end($args);
  
  foreach ($arr1 as $k1 => $v1) {
    foreach ($arr2 as $k2 => $v2) {
      $diff = $key_compare_func($k1, $k2);
    
      //var_dump('k1=' . $k1 . ', k2=' . $k2 . ', diff=' . $diff);
      
      if ($diff === 0) {
        $arr_matched[$k1] = $v1;
      } else {
        $arr_unmatched[$k1] = $v1;
      }
    }
  }
  
  if (count($args) <= 3) {
    return $arr_matched;
  }
  
  array_splice($args, 0, 2, [$arr_unmatched]);
  
  return array_merge($arr_matched, call_user_func_array('_array_intersect_ukey', $args));
}
/*
array_intersect_ukey
string(12) "a=bbb; b=aab"
string(21) "literal comparison: 1"
string(12) "a=bbb; b=ccb"
string(22) "literal comparison: -1"
string(12) "a=abb; b=bbb"
string(22) "literal comparison: -1"
string(12) "a=aab; b=abb"
string(22) "literal comparison: -1"
string(22) "a=aab; b=/[a-z]b[a-z]/"
string(22) "a=abb; b=/[a-z]b[a-z]/"
string(22) "a=abb; b=/c[a-z][a-z]/"
array(0) {
}
_array_intersect_ukey
string(22) "a=aab; b=/[a-z]b[a-z]/"
string(22) "a=bbb; b=/[a-z]b[a-z]/"
string(22) "a=ccb; b=/[a-z]b[a-z]/"
string(22) "a=abb; b=/[a-z]b[a-z]/"
string(22) "a=aab; b=/c[a-z][a-z]/"
string(22) "a=ccb; b=/c[a-z][a-z]/"
array(3) {
 ["bbb"]=>
 string(0) ""
 ["abb"]=>
 string(0) ""
 ["ccb"]=>
 string(0) ""
}*/
?>