Can someone help me find out why I'm getting this error?
I have an if statement as follows
if (x + ship.size) <= 10
I retrieve x from the regex expression and back expression:
(1,2) =~ /(\d+),(\d+)/
x, y = $1, $2
and I retrieve ship.size from a similar regex expression in a class object.
From my understanding, using \d in both my regex expressions is making ship.size an integer as well as x. Thus, shouldn't + be treated as addition rather than an undefined method? Any help would be appreciated. Thank you.
Regular expressions operate on strings. Even with \d the match will still be a string:
"foo123bar"[/\d+/] #=> "123"
# ^---^ note the quotes, this is a string
If you want an integer, you have to convert the result yourself, e.g. via to_i:
"foo123bar"[/\d+/].to_i #=> 123
# ^^^ this is an integer
And if no match is found, you'll get nil:
"fooxyzbar"[/\d+/] #=> nil
Regarding your error message:
NoMethodError: undefined method `+' for nil:NilClass
means that the receiver of + was nil. In your code:
if (x + ship.size) <= 10
that receiver is x, so x is nil. You basically have:
if (nil + ship.size) <= 10
Double-check how you retrieve x. Something like this should work:
"123,456" =~ /(\d+),(\d+)/
x = $1.to_i #=> 123
y = $2.to_i #=> 456