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List:       php-internals
Subject:    Re: [PHP-DEV] strtod and NaN vs. zero
From:       2.124.144.170
Date:       2016-10-25 15:21:37
Message-ID: 0C.13.24108.B987F085 () pb1 ! pair ! com
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Hi,

Marc Bennewitz wrote:
> It's totally true that on casting non numeric string to integer will
> result in 0 but that's a different type even if it's also a numeric type.
>
>  From my understanding PHP tries to cast from one type to another by
> loosing as less information as possible. In this case I see a non
> numeric string that gets casted to a float will loose exactly this
> information that it's "Not a Number" where it would be possible to keep
> this information. On casting this to int there is of course no
> possibility to keep it but I don't see where it's inconsistent as it's a
> different type used for different use-cases.

(int) and (float) are lossy and have always been so. If you want PHP to 
complain when you give it something non-numeric, rather than coerce to 
0, there are alternatives.

> Having mathematical operations with non numeric strings should result in
> the same behavior as NaN will result in NaN which makes sense and I
> don't see where it will throw lots on WARNINGS or TypeErrors as it's
> still a float.

Because previously it would be an integer. "foo" + "bar" currently gives 
an integer 0. Now it would give you a float NaN. That has potential 
knock-on effects.

Thanks.

-- 
Andrea Faulds
https://ajf.me/

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