Ruby string/integer typing rage.

str_to_i.rb

# The principle of moderate-to-infuriating surprise.

irb(main):001:0> "23".to_i
=> 23
irb(main):002:0> "23foobar".to_i
=> 23
irb(main):003:0> "foo23bar".to_i
=> 0
irb(main):004:0> "".to_i
=> 0

# The only safe way. With thanks to @eazynow

irb(main):001:0> begin
irb(main):002:1*     Integer("23foobar")
irb(main):003:1> rescue ArgumentError
irb(main):004:1>     "yey"
irb(main):005:1> end
=> "yey"

Integer("23foobar") rescue nil