如何使用php函数来压缩和优化代码？

<?php
function compress_code($code) {
  // 删除多余的空格和换行符
  $code = preg_replace('/s+/', ' ', $code);
  $code = preg_replace('/s?({|}|(|)|[|])s?/', '$1', $code);
 
  // 删除多余的分号
  $code = preg_replace('/;s?}/', '}', $code);
 
  return $code;
}
 
$code = "
  function hello_world() {
    echo 'Hello World!';
  }
";
 
$compressed_code = compress_code($code);
echo $compressed_code;
?>

<?php
function get_data_from_cache($key) {
  // 检查缓存中是否已经存在数据
  if (cache_exists($key)) {
    $data = get_data_from_cache($key);
  } else {
    // 从数据库或其他资源获取数据
    $data = get_data_from_db($key);
  
    // 将数据保存到缓存中
    save_data_to_cache($key, $data);
  }
  
  return $data;
}
 
$data = get_data_from_cache('my_key');
echo $data;
?>

<?php
if (isset($_GET['name'])) {
  $name = $_GET['name'];
  echo "Hello, " . $name;
}
?>

<?php
if (!empty($_GET['name'])) {
  $name = $_GET['name'];
  echo "Hello, " . $name;
}
?>

<?php
$numbers = array(1, 2, 3, 4, 5);
$length = count($numbers);
echo "The length of array is: " . $length;
?>