(PHP 5, PHP 7, PHP 8)
array_udiff — 用回調函數比較數據來(lái)計算數組的差集
使用回調函數比較數據，計算數組的不同之處。和 array_diff() 不同的是，前者使用內置函數進(jìn)行數據比較。
array第一個(gè)數組。
arrays要對比的數組。
value_compare_func回調對照函數。
在第一個(gè)參數小于，等于或大于第二個(gè)參數時(shí)，該比較函數必須相應地返回一個(gè)小于，等于或大于 0 的整數。
返回 array 里沒(méi)有出現在其他參數里的所有值。
示例 #1 array_udiff() 使用 stdClass 對象的例子
<?php
// 要對比的數組
$array1 = array(new stdclass, new stdclass,
new stdclass, new stdclass,
);
$array2 = array(
new stdclass, new stdclass,
);
// 為每個(gè)對象設置一些屬性
$array1[0]->width = 11; $array1[0]->height = 3;
$array1[1]->width = 7; $array1[1]->height = 1;
$array1[2]->width = 2; $array1[2]->height = 9;
$array1[3]->width = 5; $array1[3]->height = 7;
$array2[0]->width = 7; $array2[0]->height = 5;
$array2[1]->width = 9; $array2[1]->height = 2;
function compare_by_area($a, $b) {
$areaA = $a->width * $a->height;
$areaB = $b->width * $b->height;
if ($areaA < $areaB) {
return -1;
} elseif ($areaA > $areaB) {
return 1;
} else {
return 0;
}
}
print_r(array_udiff($array1, $array2, 'compare_by_area'));
?>
以上例程會(huì )輸出：
Array
(
[0] => stdClass Object
(
[width] => 11
[height] => 3
)
[1] => stdClass Object
(
[width] => 7
[height] => 1
)
)
示例 #2 array_udiff() 使用 DateTime 對象的例子
<?php
class MyCalendar {
public $free = array();
public $booked = array();
public function __construct($week = 'now') {
$start = new DateTime($week);
$start->modify('Monday this week midnight');
$end = clone $start;
$end->modify('Friday this week midnight');
$interval = new DateInterval('P1D');
foreach (new DatePeriod($start, $interval, $end) as $freeTime) {
$this->free[] = $freeTime;
}
}
public function bookAppointment(DateTime $date, $note) {
$this->booked[] = array('date' => $date->modify('midnight'), 'note' => $note);
}
public function checkAvailability() {
return array_udiff($this->free, $this->booked, array($this, 'customCompare'));
}
public function customCompare($free, $booked) {
if (is_array($free)) $a = $free['date'];
else $a = $free;
if (is_array($booked)) $b = $booked['date'];
else $b = $booked;
if ($a == $b) {
return 0;
} elseif ($a > $b) {
return 1;
} else {
return -1;
}
}
}
// 為每周日程創(chuàng )建日歷
$myCalendar = new MyCalendar;
// 為本周預約一些日程
$myCalendar->bookAppointment(new DateTime('Monday this week'), "Cleaning GoogleGuy's apartment.");
$myCalendar->bookAppointment(new DateTime('Wednesday this week'), "Going on a snowboarding trip.");
$myCalendar->bookAppointment(new DateTime('Friday this week'), "Fixing buggy code.");
// 通過(guò)對比 $booked 日期和 $free 日期獲取空閑的天數
echo "I'm available on the following days this week...\n\n";
foreach ($myCalendar->checkAvailability() as $free) {
echo $free->format('l'), "\n";
}
echo "\n\n";
echo "I'm busy on the following days this week...\n\n";
foreach ($myCalendar->booked as $booked) {
echo $booked['date']->format('l'), ": ", $booked['note'], "\n";
}
?>
以上例程會(huì )輸出：
I'm available on the following days this week... Tuesday Thursday I'm busy on the following days this week... Monday: Cleaning GoogleGuy's apartment. Wednesday: Going on a snowboarding trip. Friday: Fixing buggy code.
注意: 注意本函數只檢查了多維數組中的一維。當然，可以用
array_udiff($array1[0], $array2[0], "data_compare_func");來(lái)檢查更深的維度。