Re: PHP can't compare...

Rasmus Lerdorf wrote: > > > But I don't want to do this! I want to compare php numbers, which can be either > > strings or floats, > > in php! This already works fine when the php number is "passed" as a string, I > > just want it to also > > work when it's passed as a float/double! > > Which is not possible. > > > floor(string(8.2 - 0.2)) == 8.) > > Sure, this will work for exactly the same reason that > floor(round(8.2 - 0.2) == 8.0) will work. What you are implying is that > we should always be doing an implicit round() which is not a good idea. > This should be something that is up to the developer. > > > So why doesn't php do this cast/round for me? That's my question. > > Because that would impose rounding errors and remove the develpor's > flexibility for controlling this exactly. > > -Rasmus But my suggestion only produces rounding errors when the developer is trying to operate on floats with results of precision greater than 14 decimals. These developers should already know they MUST use bc or gmp in such cases. You may say it should be "up to the developer", but there is no discretion that you are leaving with the developer that can be meaningfully used! Instead you are saying that we cannot protect users who are using less than 14 decimals through rounding because of the potential loss of control for developers who are using 14 decimals or more who have ALREADY been told NOT to use this function! This strikes me as frankly bizarre! The current situation benefits noone! My suggestion benefits EVERYONE except the small set of developers using medium/high precision (> 14 decimals) for whom these functions are already inappropriate. They, therefore, lose nothing! The rest do gain, a lot! REMEMBER: This is emphatically NOT the same case as rounding floats on general arithmetic functions where the rounding errors can easily propagate, rounding then would be a VERY BAD THING. This rounding will NEVER "pollute" a float, since the functions/operators do not return floats! George