JavaScript Review session conducted during the Solid JavaScript Session in Voyager Innovations, May 25, 2015. Coverage includes: - Variables - Objects - This - Hoisting - Functions - Immediate - Currying - Constructor Functions - Closures Companion repo: https://github.com/diwadm/solid-js-coding

1. S O L I D
J AVA S C R I P T
C O D I N G
M A Y 2 4 , 2 0 1 5 - D I WA D E L M U N D O / V O YA G E R I N N O VA T I O N S

2. JavaScript is …

3. – C H A R L E S J O S E P H U Y
“swiss army knife romance.”
JavaScript is …

4. – M A . C Z A R I N A S . B O N G AT
“is a cool scripting language but hard to learn.”
JavaScript is …

5. – S A M U E L F R A N C I S C O
“the language to rule them all.”
JavaScript is …

6. - S E T A B A S E S TA N D A R D F O R
J AVA S C R I P T D E V E L O P M E N T
W H Y A R E W E H E R E ?
- F O S T E R A
C O L L A B O R AT I V E
E N V I R O N M E N T F O R
J AVA S C R I P T
K N O W L E D G E L E A R N I N G
- G E T T O G E T H E R A N D
H AV E L U N C H !

7. O V E R V I E W O F T O D AY ’ S S E S S I O N
• JavaScript Review - Diwa del Mundo
• Object-Oriented Programming in JS - Zander
Magtipon
• JavaScript Anti-Patterns - Russell Santos
• JS Race Conditions - Arisa Ochavez
• ECMAScript 6 - Ruel Pagayon

8. git clone https://goo.gl/fNA4Ex
// If you have nvm:
nvm use v0.12
node

9. J AVA S C R I P T R E V I E W
• Variables, Globals
• Functions (Scopes, Constructor Functions, Self-
executing)
• Object Literals and the “new” operator
• Closures

10. 1 . VA R I A B L E S . J S
• Primitives
• typeof

11. 2 . O B J E C T-
L I T E R A L S . J S
• You can create variables
either by literals or built-in
constructors
• Object literals: key-value
notation
• For non-custom objects,
you’ll use literals most of
the time

12. 3 . VA R S -
G L O B A L S . J S
• Variables are declared via
‘var’, optional but
recommended
• Not using ‘var’ makes your
variable an implied global
• Implied globals can be
deleted, explicit globals
cannot be deleted

13. 4 . N O T E S - O N - T H I S . J S
• The variable ‘this’ inside a non-constructor function points to the
global object
global

14. 5 . H O I S T I N G . J S
• Hoisting refers to the
‘jump to top’ behaviour of
the JavaScript interpreter
• Interpreter “preprocesses”
code

15. 6 . F U N C T I O N S . J S
• Functions are 1st-class objects in JS:
they have properties and methods
• They provide scope
• Created dynamically, assigned,
copied by reference
• Can be passed as arguments to
other functions
• Types: function declarations,
functional expression, named
functional expression

16. I M M E D I AT E
F U N C T I O N S A N D
C U R RY I N G
• Immediate functions
executes immediately -
good for initialisation
• Currying - partial
application of functions -
good when calling
functions with similar
arguments

17. N E W

18. 7 . C O N S T R U C T O R -
F U N C T I O N S . J S
• You can create object
instances using the ‘new’
operator
• “Objects” are defined via
constructor functions
• ‘this’ refers to the instance

19. http://www.thehindu.com/multimedia/dynamic/00846/20SM_VIJAY_846767f.jpg

20. – C H A P T E R 3 , E X P E R T J AVA S C R I P T ( D A G G E T T )
A closure is the act of binding all free variables and
functions into a closed expression that persist
beyond the lexical scope from which they were
created.

21. 8 . C L O S U R E S . J S
• Most basic definition: an
outer function that returns
an inner function
• A way to have access to
variables and functions
that it shouldn’t have

22. S U M M A RY
• Use literals.
• Define objects through constructor functions.
• Understand ‘this’.
• Learn functions by heart.
• Whatever happens, make sure you know closures.

23. Colophon
The animal in the photo in this presentation is a Tarsier.
References
See References.md
JavaScript Patterns
Expert JavaScript