Question

I am checking this PHP quality control tool: PHP_CodeSniffer

In its documentation page Example Section, it shows Usage of the tool:

 $ phpcs /path/to/code/myfile.php

 FILE: /path/to/code/myfile.php
 --------------------------------------------------------------------------------
 FOUND 5 ERROR(S) AFFECTING 2 LINE(S)
 --------------------------------------------------------------------------------
   2 | ERROR | Missing file doc comment
  20 | ERROR | PHP keywords must be lowercase; expected "false" but found "FALSE"
  47 | ERROR | Line not indented correctly; expected 4 spaces but found 1
  51 | ERROR | Missing function doc comment
  88 | ERROR | Line not indented correctly; expected 9 spaces but found 6
 --------------------------------------------------------------------------------

on line 2

20 | ERROR | PHP keywords must be lowercase; expected “false” but found “FALSE”‘, my question is why lower case “false” and “true”.

according to PHP’s documentation: “A boolean expresses a truth value. It can be either TRUE or FALSE”

Answer 1

Yes, PHP documentation says “TRUE or FALSE” but also says;

Syntax

To specify a boolean literal, use the keywords TRUE or FALSE. Both
are case-insensitive.

So, even if PHP_CodeSniffer says

PHP keywords must be lowercase; expected “false” but found “FALSE”

it doesn’t matter actually. You can change all boolean values to lowercase to skip this error message if you really care that much.