如何修复PHP中的隐形空间问题？ [重复]

Question

This question already has an answer here:

• How to fix “Headers already sent” error in PHP 11 answers

As a result,functions like session_start and setcookie can't run successfully,reporting:

Cannot modify header information - headers already sent by

But the target file is like this:

1 <?php
2 session_start(); 

How to fix it?

FOUNDINGS

I've found the problem,the utf-8 formated files become utf-8+BOM after uploading to the server,so I've temporarily solved the problem by saving it as utf-8 again.

BUT,there are lots of other files with the same problem,how can I batch solve the issue?

</div>

Answer 1

There's only one way to fix it: find the space! It's somewhere, it's always somewhere.

To fix, try the three steps in this article.