CODEWITHSUNDEEP
phptypestype-hinting
tomsseisums
tomsseisums

Reputation: 13367

type hinting and the reason(s) behind their limitations

Are object and array really the only types allowed for type hinting?

Plus, they state in documentation that standard types string and int cannot be type hinted also.

And that makes me more curious. What is the reason behind only allowing two type hints and the dropping of standard ones?

Thanks in advance!

Upvotes: 5

Views: 435

Answers (2)

NikiC
NikiC

Reputation: 101936

PHP 5.3 currently supports only array and ClassName typehints.
The upcoming PHP 5.4 version will also support callable typehints.

The reason why scalar typehints are currently not supported is that their behavior in a weakly typed language is unclear:

  • Should an error be thrown, even if it's just the difference between 1 and '1'? -> Against PHP spirit
  • Should normal PHP casts be applied? In that case 'hallo' would give 0 for an int typehint -> Unintuitive
  • Should some more strict casting rules apply?

That's the reason why the scalar typehint implementation was backed out of PHP 5.4 - there was no consensus on this question.

Upvotes: 8

vicentazo
vicentazo

Reputation: 1799

Yes, only array and object are the types allowed for type hinting.

http://www.php.net/manual/en/language.oop5.typehinting.php

See the last line:

Type Hints can only be of the object and array (since PHP 5.1) type. Traditional type hinting with int and string isn't supported.

Upvotes: 0

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