CODEWITHSUNDEEP
phpfloating-pointnumbers
Nazariy
Nazariy

Reputation: 6088

How to define that float is half of the number?

What would be the most efficient way to say that float value is half of integer for example 0.5, 1.5, 10.5?

First what coming on my mind is:

$is_half = (($number - floor($number)) === 0.5);

Is there any better solutions?

Upvotes: 0

Views: 1702

Answers (2)

ircmaxell
ircmaxell

Reputation: 165261

Due to floating point precision errors, you usually should check to see that the difference is below some low amount (but note that 0.5 is representable exactly, so it shouldn't be a problem, but it is in general with floats).

So your code is good for your specific sense, in general, you might want to do:

if (abs($number - floor($number) - $decimal) < 0.0001) {

Where $decimal is your looking difference: 0.5.

Upvotes: 4

Neigyl R. Noval
Neigyl R. Noval

Reputation: 6038

if(abs($number) - (int)(abs($number)) == 0.5) {
    // half of an integer.
}

Upvotes: 0

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