For example, is the following program meaningful, and if so what should it print?
<?php
FuncTIon fOo($x) { eChO $x; }
FOO('bar');
IF (TRuE) { echO 'qux'; }
?>
My interpreter runs it and prints barqux
, implying the keywords are not case-sensitive:
$ php case_sensitive_keywords.php
barqux
$ php --version
PHP 5.5.7-1+sury.org~precise+1 (cli) (built: Dec 12 2013 21:37:40)
However, this same question was asked last year, and the answers say that keywords are case-sensitive, in direct contradiction to what my PHP interpreter appears to tell me!
Case sensitive (both user defined and PHP defined)
Case insensitive (both user defined and PHP defined)
No. Keywords are case-insensitive. Lerdorf et al., Programming PHP, page 17:
The names of user-defined classes and functions, as well as built-in constructs and keywords such as
echo
,while
,class
, etc., are case-insensitive. Thus, these three lines are equivalent:echo("hello, world"); ECHO("hello, world"); EcHo("hello, world");
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With