Why is there a php namespace issue?

Question

PHP

Hello! I am new to PHP (4 days programming on it). Got to the namespaces.
There are 3 files:
1st - code1.php -

<?php namespace CodeOne;
function sayHi(){
  print "Передаю привет из code1";
}
?>

2nd - code2.php -

<?php namespace CodeTwo;
function sayHi(){
  print "Передаю привет из code2";
}
?>

3rd - general.php -

<?php 
require("code1.php");
require("code2.php");
print "файл general.php успешно подключен";
\CodeTwo\sayHi();
?>

This is what the file folder looks like:

1. code1.php
   
2. code2.php
   
3. general.php
   

When executing general.php, the following error occurs:

Fatal error: Namespace declaration statement has to be the very first statement or after any declare call in the script in C:\OpenServer\domains\asd\code1.php on line 3

What is the problem?

Answer 1

• The namespace declaration must not be preceded by PHP code, including extra spaces.
  See more: Defining Namespaces

Answer 2

Good evening.
See the link for useful articles about namespaces.