How to return a float from a method?

Ruby
1

I am orienting in ruby and crystal. Because the syntax is so similar:

def interpolation(x,y,z)
(z - x) / (y - x)
end

puts interpolation(1,3,2)

end code
I read that the last statement in a method is returned. Why is this method returning 0? it should return 0.5

ps. how to correctly post code into this forum?

2

When you use integers, you get integer division. You can use to_f to force a number to be a float:

> 4/3
 => 1 
> 4.0/3
 => 1.3333333333333333 
> 4.to_f/3
 => 1.3333333333333333 

> def interpolation(x,y,z)
>   (z - x) / (y - x)
> end
 => :interpolation 
> interpolation(1,3,2)
 => 0 
> interpolation(1.0,3,2)
 => 0.5 
> def interpolation(x,y,z)
>   (z-x).to_f/(y-x).to_f
> end
 => :interpolation 
> interpolation(1,3,2)
 => 0.5

Three back ticks top-and-bottom.

2 Likes
3

Ah now I understand! I ended up with this for the eye-candy:

def interpolation(x,y,z)
  x = x.to_f
  y = y.to_f
  z = z.to_f
  (z - x) / (y - x)
end
1 Like