ruby-on-rails - Ruby puts string and integer on same line

Question

I just started learning Ruby and uncertain what is causing the error. I'm using ruby 1.9.3

puts 'What is your favorite number?'
fav = gets 
puts 'interesting though what about' + ( fav.to_i + 1 )

in `+': can't convert Fixnum into String (TypeError)

In my last puts statement, I thought it is a simple combination of a string and calculation. I still do, but just not understanding why this won't work

Answer 1

在 Ruby 中，您通常可以使用“字符串插值”而不是将（“连接”）字符串添加到一起

puts "interesting though what about #{fav.to_i + 1}?"
# => interesting though what about 43?

基本上，内部的任何内容#{}都会被评估，转换为字符串，然后插入到包含的字符串中。请注意，这仅适用于双引号字符串。在单引号字符串中，您将得到您输入的内容：

puts 'interesting though what about #{fav.to_i + 1}?'
# => interesting though what about #{fav.to_i + 1}?

Answer 2

( fav.to_i + 1 ) returns an Integer, and ruby does not do implicit type conversion. You have to convert it yourself by doing ( fav.to_i + 1 ).to_s to be able to add it to the string.