Modulus in Ruby always returning false

Question

I need to "translate" the following loop from JavaScript to Ruby:

for(i=0;i<=b.length-1;i++){
  if(!(i%2)){
    c+=b[i]
  }
}

Here is how I tried to write the same in Ruby:

until i == b.length-1 do
  unless i%2 == true
    c += b[i]
    i += 1
  end  
end

The modulus operator in Ruby, however, seems to return false all the time; which renders the whole condition meaningless.

What am I doing wrong?

Answer 1

You should have:

unless i%2 == 1

or, equivalently:

if i%2 == 0

The reason of unexpected behavior is that Ruby treats all values (including 0) except false and nil as "truthy" in conditional statements.