Advanced Javascript Basics

Transcript

1. Advanced JavaScript Basics @laurenvoswinkel GitHub - valarissa
2. Value Types
3. Value Types
4. Reference Types
5. Reference Types
6. Variable Scopes
7. Variable Scopes
8. Variable Scopes
9. Variable Scopes
10. Variable Scopes
11. Hoisting
12. Hoisting
13. Environments • Variable environments are defined during parsing (before execution)
14. Environments • Variable environments are defined during parsing (before execution) • Environments all contain references to their parent scope
15. Environments • Variable environments are defined during parsing (before execution) • Environments all contain references to their parent scope • Variables defined higher up the chain have a broader domain, but a lower priority
16. Environments • Variable environments are defined during parsing (before execution) • Environments all contain references to their parent scope • Variables defined higher up the chain have a broader domain, but a lower priority • Namespaces are your friend.
17. Environments • Variable environments are defined during parsing (before execution) • Environments all contain references to their parent scope • Variables defined higher up the chain have a broader domain, but a lower priority • Namespaces are your friend. • No really, namespace collisions are confusing and terrible
18. {a:0, b:3, '..':! ! ! {a:42, '..':! ! ! ! ! {...}! ! ! }! }
19. Functions
20. Functions
21. Currying, Closures and Partial Application
22. Functions as Arguments
23. Callback Pyramids
24. Dismantling Pyramids
25. Problem:
26. .call() and .apply()
27. .call() and .apply() • allows execution of function with any environment
28. .call() and .apply() • allows execution of function with any environment • methods are executed with the object their associated with as their default environment
29. .call() and .apply() • allows execution of function with any environment • methods are executed with the object their associated with as their default environment • .call() accepts arguments individually
30. .call() and .apply() • allows execution of function with any environment • methods are executed with the object their associated with as their default environment • .call() accepts arguments individually • .apply() accepts arguments as an array or
 array-like object
31. arguments
32. arguments
33. arguments • functions have a length
34. arguments • functions have a length • length is equal to number of named arguments
 (the function’s arity)
35. arguments • functions have a length • length is equal to number of named arguments
 (the function’s arity) • all arguments, even accounted ones are available in arguments object
36. arguments • functions have a length • length is equal to number of named arguments
 (the function’s arity) • all arguments, even accounted ones are available in arguments object • unaccounted arguments can be discerned by using Array.slice with arguments’ as the context
37. arguments
38. "Classes" • JavaScript doesn't have traditional classes
39. "Classes" • JavaScript doesn't have traditional classes • JavaScript "classes" are objects with two requirements:
40. "Classes" • JavaScript doesn't have traditional classes • JavaScript "classes" are objects with two requirements: • Constructor Function
41. "Classes" • JavaScript doesn't have traditional classes • JavaScript "classes" are objects with two requirements: • Constructor Function • Prototype
42. Constructors! Are! Functions
43. Functions! Are! Constructors
44. new
45. Example
46. new changes a function to return the ‘this’ meta-object
47. Example
48. More Example
49. Constructor Helpers
50. Prototypes! Are! Objects
51. All! Objects! Can be used as! Prototypes
52. Example
53. Inheritance
54. Problem
55. Objects are Reference Types
56. Inheritance
57. Inheritance Redux
58. Fixed!
59. Overview • Environments & Environment Hierarchies
 - scopes
 - var keyword
 - hoisting
 - variable lookup • Functions as "First-Class" Objects
 - closures vs. pure functions
 - currying
 - partial application
 • Callbacks & Avoiding Callback Pyramids
 - callbacks, in principle
 - callbacks that use callbacks
 - avoiding callback pyramids (why are they necessary?)
60. Overview (cont'd) • .call() & .apply()
 - passing environment contexts
 - arguments object • Prototypal Programming
 - Constructors
 - Constructor Methods
 - Instance Methods • Object Oriented Approaches
 - Inheritance
 - Prototype chaining
61. Done!
62. “Final”! Questions?
63. @laurenvoswinkel! GitHub: valarissa
64. We’re Hiring!