Why is the semicolon optional in the last statement in php?

Question

I was surprised when I ran the following code in my editor:

<?php      echo "hello";     echo "world"  ?> 

As it can be easily seen, a semicolon (;) is missing from the code, however it still works!

How this works and why ; is {0,1} here?

Answer 1

Because the close tag implies a semicolon. You can read more about this in the manual under Instruction separation.

And a quote from there:

As in C or Perl, PHP requires instructions to be terminated with a semicolon at the end of each statement. The closing tag of a block of PHP code automatically implies a semicolon; you do not need to have a semicolon terminating the last line of a PHP block. The closing tag for the block will include the immediately trailing newline if one is present.

An example to prove this:

1. script with missing semicolon at the end, but with closing tag:

<?php     echo "1";     echo "2"           //^ semicolon missing ?> 

output:

12 

2. script with missing semicolon at the end, but without closing tag:

<?php     echo "1";     echo "2"           //^ semicolon missing (closing tag missing) 

output:

Parse error: syntax error, unexpected end of file, expecting ',' or ';' in