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Ruby

Posted by leonvsthings
leonvsthings
12,236 Points

Basic birth year calculation

I've completed the numbers & methods parts in Ruby and wanted to calculate user's birth year with the things I've learned.

Came up with something like this:

print "How old are you? "
age = gets.chomp #if I don't add chomps the number gets /n and it's not recognized.
print "And what year are we in? "
year = gets.chomp 
birthyear = year - age
print "That means you were born in #{birthyear}"

When I run this, I get: 

hello.rb:11:in `<main>': undefined method `-' for "2016":String (NoMethodError)                                                                                                                            Did you mean?  -@

What am I doing wrong?

1 Answer

Seth Kroger
Seth Kroger
56,413 Points
Seth Kroger
Seth Kroger
56,413 Points

There is difference between text and numbers in programming. When you read the input from the console with gets, it's always a text string (the 's' in gets). It still need to be converted into a number that the computer can understand as a number. For an integer (whole number) that is done with to_i in ruby.

print "How old are you? "
age = gets.chomp.to_i # changes the string to an integer number.
print "And what year are we in? "
year = gets.chomp.to_i
birthyear = year - age
print "That means you were born in #{birthyear}"
leonvsthings
leonvsthings
12,236 Points

Thanks, that makes sense! I'll play around with the code and I just realized that I don't know how to properly use new line if it's coming after a string like #{birthyear}/n. Jason mentions that he'll show it later on but I haven't made it that far yet.