String to number
puts "10".to_i # => 10: convert string to integer puts "10".to_i(2) # => 2: argument is radix: between base-2 and base-36 puts "10x".to_i # => 10: nonnumeric suffix is ignored. Same for oct, hex puts " 10".to_i # => 10: leading whitespace ignored puts "ten".to_i # => 0: does not raise exception on bad input puts "10".oct # => 8: parse string as base-8 integer puts "10".hex # => 16: parse string as hexadecimal integer puts "0xff".hex # => 255: hex numbers may begin with 0x prefix puts " 1.1 dozen".to_f # => 1.1: parse leading floating-point number puts "6.02e23".to_f # => 6.02e+23: exponential notation supported