How to avoid unexpected end of input error when adding extra method argument

Question

I am testing a method with multiple arguments. For some reason, Ruby will run fine if I have just one argument to the calculate() method, but when I add a second, it causes an unexpected end of input error.

This is the code:

def set_weights
    actual_weight = @desired_weight.to_i - 45
    calculate (actual_weight, 65)
end

def calculate (remaining_weight, plate_weight)
end

The error message is:

    weights.rb:31: syntax error, unexpected ',', expecting ')'
    calculate (actual_weight, 45)
                             ^

If I remove the second argument, I get no errors.

def set_weights
    actual_weight = @desired_weight.to_i - 45
    calculate (actual_weight)
end

def calculate (remaining_weight)

end

you should remove space between `calculate` and `(remaining_weight, place_weight)` — Oleksandr Holubenko, Jan 23 '17 at 19:53
That worked, thanks! Does ruby take into account white space when calling and declaring methods? — JoYKim, Jan 23 '17 at 19:55
[Here](http://stackoverflow.com/questions/26480823/why-does-white-space-affect-ruby-function-calls) you can get an explanation for that behaviour — jmm, Jan 23 '17 at 20:30

score 1 · Answer 1 · answered Jan 23 '17 at 21:27

Define a function:

irb(main):012:0> def add(x, y) x+y end 
`=> nil

If you call it without a space between the arguments and the function:

irb(main):013:0> add(5,6)
=> 11

With the space:

irb(main):014:0> add (5,6)
SyntaxError: (irb):14: syntax error, unexpected ',', expecting ')'
add (5,6)
       ^
from /usr/bin/irb:12:in `<main>'

The extra space before the argument list causes the interpreter to throw a SyntaxError. Since ruby functions can be run with or without parens, including a space makes the interpreter think it is about to receive arguments for the function - instead it receives a tuple (5,6).

Remove the space and your code will run correctly.

score 0 · Answer 2 · answered Jan 23 '17 at 19:55

0

Remove the extra space before the method call, like this:

def set_weights
    actual_weight = @desired_weight.to_i - 45
    calculate(actual_weight, 65)
end

def calculate (remaining_weight, plate_weight)
end

answered Jan 23 '17 at 19:55

jmm

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How to avoid unexpected end of input error when adding extra method argument

2 Answers2