CODEWITHSUNDEEP
language-design
Roman
Roman

Reputation: 10403

Why are PHP booleans both lower case and upper case?

Is there a difference between true and TRUE or false and FALSE in PHP?

Upvotes: 7

Views: 2762

Answers (4)

Mandrake
Mandrake

Reputation: 403

If you intend to use JSON then the standard RFC7159 says :

The literal names MUST be lowercase. No other literal names are allowed.

And from Php 5.6 :

json_decode() now rejects non-lowercase variants of the JSON literals true, false and null at all times, as per the JSON specification

And according to PSR-2 standard :

PHP keywords MUST be in lower case.

The PHP constants true, false, and null MUST be in lower case.

Ps.: I could not post link to the RFC7159 because of SO limitations.

Upvotes: 5

mario
mario

Reputation: 145482

Constants are case-sensitive per default. But for symmetry to the other identifier namespaces, they can be defined case-insensitively:

 define("mixedCASE", 123, TRUE);

 print MiXeDcAsE;

And that's just how TRUE and FALSE were pre-declared. (They aren't parser/language builtins.)

Upvotes: 2

Kodlee Yin
Kodlee Yin

Reputation: 1089

Nope, the PHP Parser isn't very fussy when it comes to TRUE, true and FALSE, false

Upvotes: 1

Interrobang
Interrobang

Reputation: 17434

http://php.net/manual/en/language.types.boolean.php

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

Upvotes: 0

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