php - PHPを使用して、以下の段落で文字「t」の数を見つける方法

Question

$a='Would you like to have responses to your questions sent to you via email'

for($a as $b=>c){

}

解決策を教えてください

Answer 1

<?php echo substr_count($a, 't'); ?>

Answer 2

これをチェック

<?php

$a = 'Would you like to have responses to your questions sent to you via email';

$t_explod = explode('t', strtolower($a));

echo count($t_explod) - 1;
?>

Answer 3

ここに解決策がありますが、必ずしも最善ではありません

$letterCount = array_count_values(
    str_split(strtolower($a))
);
$tCount = (isset($letterCount['t'])) ? $letterCount['t'] : 0;

Answer 4

$count = preg_match_all('/t/', $str);