除了第一个单词之外，将字符串数组的所有字符串都设置为小写

Supposing I have an array Tomat, Ost How can I accomplish so it is like this: Tomat, ost?

$ingredient_a = Array('Tomat', 'Ost');
echo implode(', ', $ingredient_a);

Use ucfirst and array_map with strtolower

echo ucfirst(implode(', ', array_map('strtolower',$ingredient_a)));

$ingredient_a = array('Tomat', 'Ost');
$new = array();

foreach($ingredient_a as $key => $value) {
    $key == 0 ? $new[] = $value : $new[] = strtolower($value);
}

echo implode(', ', $new);