php从字符串中提取值

$string = "Hello, my name is John Doe.";
$pattern = '/name is (.*) Doe/';
preg_match($pattern, $string, $matches);
$name = $matches[1];
echo $name; // 输出 "John"

$string = "Hello, my name is John Doe.";
$start = strpos($string, "name is ") + strlen("name is ");
$end = strpos($string, " Doe");
$name = substr($string, $start, $end - $start);
echo $name; // 输出 "John"

$string = "Hello, my name is John Doe.";
$parts = explode(" ", $string);
$name = $parts[7];
echo $name; // 输出 "John"