如果您只是想避免达到 PHP 的 100 级递归限制，那么

If you are just looking to avoid hitting PHP's 100 level recursion limit then

count(debug_backtrace()); 

应该足够了.否则，您无法选择传递深度参数，尽管 precrement 运算符使其更清晰，如下面的示例所示.

should be sufficient. Otherwise you've no choice to pass a depth argument, though the precrement operator makes it somewhat cleaner as seen in the example below.

function recursable ( $depth = 0 ) {
  if ($depth > 3) {
    debug_print_backtrace();
    return true;
  } else {
    return recursable( ++$depth );
  }
}