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Countable::count

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

Countable::count — オブジェクトの要素の数を数える

説明

public Countable::count(): int

このメソッドは、 count() 関数の value パラメーターが Countable を実装している場合に実行されます。

パラメータ

この関数にはパラメータはありません。

戻り値

数えたカスタムの結果を整数値として返します。

例

例1 Countable::count() の例

<?php

class Counter implements Countable
{
private $count = 0;

public function count(): int
{
return ++$this->count;
}
}

$counter = new Counter;

for ($i = 0; $i < 10; ++$i) {
echo "I have been count()ed " . count($counter) . " times\n";
}

?>

上の例の出力は、 たとえば以下のようになります。

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