php – 如何在没有标题重定向的情况下将用户发送到另一个URL？

i read that header redirects can achieve this but no code can go before it. that it must be first on the page else it wont work.

那是错的.在此之前必须没有输出.因此,你必须确保,你之前没有回声,打印,？>某事<？php(或其他).

if (true)  {
  header('Location: ' . $url,false,302);
  exit; // Ensures,that there is no code _after_ the redirect executed
}

你可以准备好一切about it in the official manual.特别是：

Remember that header() must be called before any actual output is sent,either by normal HTML tags,blank lines in a file,or from PHP. It is a very common error to read code with include(),or require(),functions,or another file access function,and have spaces or empty lines that are output before header() is called. The same problem exists when using a single PHP/HTML file.