Ruby/String/Convert Number

"100".class # => String
"100".to_i # => 100
"100".to_i.class # => Fixnum

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

"200".class # => String
"200".to_f # => 200.0
"200".to_f.class # => Float