convert string to integer then add 1 with RubyMotion

Question

Can someone tell me why the following code is wrong:

def pickerView(pickerView, didSelectRow:row, inComponent:component)
@myLabel.text = "#{row+1}"  
end

def remain
@remainLabel.text = @myLabel.text
end

def left
remain.to_i (+1)
end

I'm calling the "left" method via a button click but I get "invalid radix 1" as an error. I have tried various different configurations including with and without the brackets and with and without spaces. Basically, whatever I do, I either get an error or else just the selected number from the picker without the 1 added.

Answer 1

You want:

remain.to_i + 1

The method remain returns a string, the string in @myLabel.text. When you write:

remain.to_i (+1)

Ruby thinks you are passing the parameter (+1) to the to_i method. It turns out that to_i does take a parameter which is the base (or radix) you want it to use to interpret the string.

puts "FF".to_i(16)  // prints "255"
puts "101".to_i(2)  // prints "5"

Base 1 is an invalid base hence the invalid radix message. The default base is 10, so

puts "123".to_i(10)  // prints "123"
puts "123".to_i      // prints "123"