Primitive Data Types

Transcript

1. Data Types Thursday, September 3, 2009
2. undefined any variable that has not been assigned a value and any property of an object that does not exist Thursday, September 3, 2009
3. null indicates that variable has been declared but defined empty Thursday, September 3, 2009
4. number • values that can be processed and calculated • can be positive or negative • represented internally as a double, accurate to 14 or 15 digits Thursday, September 3, 2009
5. number Thursday, September 3, 2009
6. number calculations Thursday, September 3, 2009
7. Math! http://www.w3schools.com/jsref/jsref_obj_math.asp Thursday, September 3, 2009
8. string • sequence of characters enclosed with quotation marks • can use single or double quotes • cannot use quotes of the same type inside the same type unless they are escaped http://www.w3schools.com/jS/js_obj_string.asp Thursday, September 3, 2009
9. string characters Thursday, September 3, 2009
10. string characters Thursday, September 3, 2009
11. everything is zero indexed j a v a s c r i p t 0 1 2 3 4 5 6 7 8 9 Thursday, September 3, 2009
12. string characters (shortcut) Thursday, September 3, 2009
13. string characters (shortcut) Thursday, September 3, 2009
14. string escaping cannot use quotes of the same type inside the same type unless they are escaped Thursday, September 3, 2009
15. same quotes no escape FAIL! Thursday, September 3, 2009
16. meet the escape character \ Thursday, September 3, 2009
17. same quotes with escape WIN! Thursday, September 3, 2009
18. same quotes no escape FAIL! Thursday, September 3, 2009
19. same quotes with escape WIN! Thursday, September 3, 2009
20. different quotes WIN! Thursday, September 3, 2009
21. different quotes WIN! Thursday, September 3, 2009
22. string length Thursday, September 3, 2009
23. string search Thursday, September 3, 2009
24. changing string case Thursday, September 3, 2009
25. string to number Thursday, September 3, 2009
26. string to number Thursday, September 3, 2009
27. string to number Thursday, September 3, 2009
28. “class is awesome”.charAt(2) Thursday, September 3, 2009
29. “class is awesome”.charAt(2) “a” Thursday, September 3, 2009
30. “class is awesome”[0] Thursday, September 3, 2009
31. “class is awesome”[0] “c” Thursday, September 3, 2009
32. how do I get the length of “football” Thursday, September 3, 2009
33. how do I get the length of “football” “football”.length Thursday, September 3, 2009
34. “football”.length Thursday, September 3, 2009
35. “football”.length 8 Thursday, September 3, 2009
36. “football”.indexOf(‘e’) Thursday, September 3, 2009
37. “football”.indexOf(‘e’) -1 Thursday, September 3, 2009
38. “football”.indexOf(‘foot’) Thursday, September 3, 2009
39. “football”.indexOf(‘foot’) 0 Thursday, September 3, 2009
40. what type is: ‘asdf’ Thursday, September 3, 2009
41. what type is: ‘asdf’ “string” Thursday, September 3, 2009
42. what type is: 15 Thursday, September 3, 2009
43. what type is: 15 “number” Thursday, September 3, 2009
44. what type is: -’15’ Thursday, September 3, 2009
45. what type is: -’15’ “number” Thursday, September 3, 2009
46. 10 + 20 Thursday, September 3, 2009
47. 10 + 20 30 Thursday, September 3, 2009
48. boolean true or false http://www.w3schools.com/jS/js_obj_boolean.asp Thursday, September 3, 2009