count_chars

説明

string において各バイト値(0..255)が存在する数 を数え、様々な手法で返します。 オプションの引数 mode のデフォルトは0です。 mode により以下の値のどれかを返します。

• 0 - 各バイト値をキー、各バイトの出現回数を値とする配列。

• 1 - 0と同じですが、各バイト値の出現回数がゼロより大きいものの 一覧となります。

• 2 - 0と同じですが、各バイト値の出現回数がゼロであるものの 一覧となります。

• 3 - 使用されている全てのバイト値を有する文字列が返されます。

• 4 - 使用されていない全てのバイト値を有する文字列が返されます。

例 1. count_chars() の例 <?php $data = "Two Ts and one F."; foreach (count_chars($data, 1) as $i => $val) {    echo "There were $val instance(s) of \"" , chr($i) , "\" in the string.\n"; } ?> 上の例の出力は以下となります。 There were 4 instance(s) of " " in the string. There were 1 instance(s) of "." in the string. There were 1 instance(s) of "F" in the string. There were 2 instance(s) of "T" in the string. There were 1 instance(s) of "a" in the string. There were 1 instance(s) of "d" in the string. There were 1 instance(s) of "e" in the string. There were 2 instance(s) of "n" in the string. There were 2 instance(s) of "o" in the string. There were 1 instance(s) of "s" in the string. There were 1 instance(s) of "w" in the string.

strpos(), substr_count() も参照ください。