Can anyone help in understanding this code in php

Question

https://code.sololearn.com/wOGa4C9gkDJK/?ref=app

Answer 1

Actually your code is:

<?php
echo 1 . print(1) . 1;
?>

The 'print' behaviour is the same that 'echo', and always return 1 ( http://php.net/manual/en/function.print.php )...
So, your instruction will output the first integer one as a string "1", the dot is for concatenate string, so returned value of print calling is appended to the output ( "1" ), and the next dot append the last integer one ( "1" ).
The 4th one as output is produced by execution of print(), and occurs before execution of echo ( which require the returned value of print() ^^ ).
To verfy that, try to change the print() argument:

<?php
echo 1 . print(2) . 1;
?>

;)

Answer 2

echo 1 . print(1) . 1;
echo 1.1.1.1

because print() always return 1