(PHP 5 >= 5.1.0, PHP 7, PHP 8)
Countable::count — 計算物件的元素數量
此函式沒有參數。
範例 #1 Countable::count() 範例
<?php
class myCounter implements Countable {
private $count = 0;
public function count() {
return ++$this->count;
}
}
$counter = new myCounter;
for($i=0; $i<10; ++$i) {
echo "我已被 count() 計算了 " . count($counter) . " 次\n";
}
?>上述範例將輸出類似以下的內容：
I have been count()ed 1 times I have been count()ed 2 times I have been count()ed 3 times I have been count()ed 4 times I have been count()ed 5 times I have been count()ed 6 times I have been count()ed 7 times I have been count()ed 8 times I have been count()ed 9 times I have been count()ed 10 times
即使在實作 Countable 介面的物件於 count() 函式中使用時會呼叫 Countable::count 方法，count 的第二個參數 $mode 對您的類別方法沒有影響。
$mode 不會傳遞給 Countable::count
<?php
class Foo implements Countable
{
public function count()
{
var_dump(func_get_args());
return 1;
}
}
count(new Foo(), COUNT_RECURSIVE);
?>
var_dump 輸出
array(0) {
}