I’m using ERB to generate a set of instructions with location data, and want to accept an offset in my input. When I try to check if that offset is present however, it sets it’s value to nil. If anyone can help explain what’s going on it’d be greatly appreciated!

Here’s the code I ran to test this, once I’d narrowed down the problem:

<%
    # apply a default value of 0 to the offset hash
    p offset.nil?
    p offset
    p offset.nil?
    p offset

    if offset.nil?
        p "I ran the code inside the if statement"
        offset = {}
        p "offset has been initialized, since it was nil"
    end

    p offset.nil?
    p offset
%>

and the output:

false
{"z"=>-10}
false
{"z"=>-10}
true
nil

If I delete the if statement, I get the expected result of:

false
{"z"=>-10}
false
{"z"=>-10}
false
{"z"=>-10}

but having that if statement (or one like it) is kind of important.