Ruby Method of the Month 2010.12. Lightning talk for the Columbus Ruby Brigade.

1. Number Conversions
Ruby Method of the Month
Kevin Munc - @muncman

2. YOU JUST NEED AN INTEGER?
RUBY CAN DO THAT.

3. Float to Integer

4. Float to Integer
Integer(123.45)

5. Float to Integer
Integer(123.45)
Kernel
method

6. Float to Integer
Integer(123.45)
=> 123
Kernel
method

7. Float to Integer

8. Float to Integer
Integer(999.99)

9. Float to Integer
Integer(999.99)
=> 999

10. Float to Integer
Integer(999.99) No
rounding
=> 999

11. Octal to Integer

12. Octal to Integer
Integer(01234)

13. Octal to Integer
Integer(01234)
=> 668

14. Hexadecimal to Integer

15. Hexadecimal to Integer
Integer(0x1234)

16. Hexadecimal to Integer
Integer(0x1234)
=> 291

17. Binary to Integer

18. Binary to Integer
Integer(0b101)

19. Binary to Integer
Integer(0b101)
‘b’ for
binary

20. Binary to Integer
Integer(0b101)
‘b’ for
binary => 5

21. Strings to Integers

22. Strings to Integers
Integer(“1234”)

23. Strings to Integers
Integer(“1234”)
=> 1234

24. Strings to Integers

25. Strings to Integers
Integer(“01234”)

26. Strings to Integers
Integer(“01234”)
=> 668

27. Strings to Integers

28. Strings to Integers
Integer(“0x123”)

29. Strings to Integers
Integer(“0x123”)
=> 291

30. Strings to Integers

31. Strings to Integers
Integer(“0b101”)

32. Strings to Integers
Integer(“0b101”)
=> 5

33. YOU JUST NEED A FLOATING POINT?
RUBY CAN DO THAT.

34. Integer to Float

35. Integer to Float
Float(123)

36. Integer to Float
Float(123)
=> 123.0

37. Octal to Float

38. Octal to Float
Float(01234)

39. Octal to Float
Float(01234)
=> 668.0

40. Hexadecimal to Float

41. Hexadecimal to Float
Float(0x1234)

42. Hexadecimal to Float
Float(0x1234)
=> 291.0

43. Binary to Float

44. Binary to Float
Float(0b101)

45. Binary to Float
Float(0b101)
=> 5.0

46. Strings to Floats

47. Strings to Floats
Works the same as the
non-Strings, just like
for Integer().

48. YOU JUST NEED A CHARACTER CODE?
RUBY CAN DO THAT, TOO.

49. ASCII Code to Integer

50. ASCII Code to Integer
Integer(?a)

51. ASCII Code to Integer
Integer(?a)
‘?’? Yep.

52. ASCII Code to Integer
Integer(?a)
‘?’? Yep.
=> 97

53. ASCII Code to Float

54. ASCII Code to Float
Float(?A)

55. ASCII Code to Float
Float(?A)
=> 65.0

56. ASCII Code to Float
Float(?A)
=> 65.0
String#getbyte(int) in Ruby 1.9
can also be used for this.

57. YOU JUST NEED SOMETHING ELSE?
RUBY CAN PROBABLY DO THAT, TOO.

58. Other Float Operations

59. Other Float Operations
123.45.to_i or to_int => 123
123.45.truncate => 123
123.45.ceil => 124
123.45.floor => 123
123.45.round => 123
123.55.round .50 rounds
=> 124

60. Some String Operations

61. Some String Operations
“123.45”.to_f => 123.45
“123.45”.to_i => 123
“101”.to_i => 101
“101”.to_i(16) base 16 => 257
“101”.to_i(8) => 65
“101”.to_i(2) => 5

62. String Corner Cases

63. String Corner Cases
“123.4a5”.to_f => 123.4
“12a3.45”.to_f => 12.0
“a123.45”.to_f => 0.0
“12a3.45”.to_i => 12
“a”.to_i(16) => 10
“010”.to_i(8) => 8

64. Questions? Pic Credits!
http://www.flickr.com/photos/jamescridland/2272701122/
http://www.flickr.com/photos/koenvereeken/2088902012/
http://www.flickr.com/photos/pinksherbet/3041510366/
http://www.flickr.com/photos/stewf/2026818238/
http://www.flickr.com/photos/enigmatic/2431902112/
http://www.flickr.com/photos/alpower/282507392/
SEE HTTP://WWW.SLIDESHARE.NET/MUNCMAN/ FOR OLD MOTMS.