如何只返回带有preg_match或preg_match_all的命名组？

/(?P<name>\w+)\s+is\s+(?P<age>\d+)\s+years\s+old/

<?php
$text = "John is 25 years old. Jane is 30 years old.";

// 使用preg_match只返回第一个匹配的命名组结果
if (preg_match('/(?P<name>\w+)\s+is\s+(?P<age>\d+)\s+years\s+old/', $text, $matches)) {
    echo "Name: " . $matches['name'] . "\n";
    echo "Age: " . $matches['age'] . "\n";
}

// 使用preg_match_all返回所有匹配的命名组结果
if (preg_match_all('/(?P<name>\w+)\s+is\s+(?P<age>\d+)\s+years\s+old/', $text, $matches)) {
    foreach ($matches['name'] as $index => $name) {
        echo "Name: " . $name . "\n";
        echo "Age: " . $matches['age'][$index] . "\n";
    }
}
?>

Name: John
Age: 25
Name: Jane
Age: 30