Ruby check if even number, float

Question

I want to check if the number is even! I tried the following:

a = 4.0
a.is_a? Integer

=> false

a.even?

=> undefined method for Float

S

Answer 1

Just keep in mind how numbers are converted:

(4.0).to_i # same as Integer(4.0)
=> 4
(4.5).to_i
=> 4
(4.9).to_i
=> 4

Using round may be safer:

(4.0).round
=> 4
(4.5).round
=> 5
(4.9).round
=> 5

Then of course you can call even as @Yu Hao wrote:

(4.5).round.even?
=> false

You can also easily observe known floats 'feature':

(4.499999999999999).round.even?
=> true
(4.4999999999999999).round.even?
=> false