Let's make stuff happen!!!

Mathematical

• Addition - ( + )
• Subtraction - ( - )
• Multiplication - ( * )
• Division - ( / )
• Modulus - ( % )
• Increment - ( ++ )
• Decrement - ( -- )
• Greater than - ( >, >= )
• Less than - ( <, <= )

Access/Assign

• Brackets - ( [ ] )
• dot - ( . ) 
• Assignment - ( = )
• Assignment - ( += )
• Assignment - ( -= )

Comparison

• Equality ( === )
• Not equal ( !== )

Logical

• And - ( && )
• Or - ( || )
• Not - ( ! )

Ignore

• ( == )
• ( != )

Other

• Grouping - ( )
• Ternary - ( ? )

Keywords

• var
• function
• for
• in
• typeof
• this
• new

I quit!!!

Mathematical

• Addition - ( + )
• Modulus - ( % )

Access/Assign

• Brackets - ( [ ] )
• dot - ( . ) 
• Assignment - ( = )

Comparison

• Equality ( === )
• Not equal ( !== )

Ignore

• ( == )
• ( != )

Keywords

• typeof

Current concerns...

remember,

don't worry about:

Phew!!!

JavaScript Memory

"I would walk 500 miles..."

"I want to ride my BICYCLE!!!"

9

// Review the slides on numbers if necessary
> 5 + 4; // Self explanatory
> 15 % 4; // Modulus, gets the remainder

// One more thing...
'I want to ride my' 

// What about...
'I would walk ' + 500 + ' miles...' //???

3

+ ' BICYCLE!!!'; // ???

String 'concatenation'

For more complex operations, read the docs!

JavaScript Memory

true

// Are these the same? (in terms of ASCII)
> 1000 === 1000; // ???
> 5000 !== 5000; // ???

// And these...?
> 'Basketball' !== 'and Mr. Curtis Blow'; // ???
> 'Sussudio' === 'Sussudio'; // ???

// What about types?
typeof 'Do the Beat Street Strut!'; // ???
typeof { starlight: 'startbright'}; // ???
typeof 8675309; // ??? 
typeof function() {}; // ???

false

true

true

"object"

"string"

"number"

"function"

Again,  DO NOT use '!=' or '=='

// 'Assignment Operator' (NOT EQUALS!)
> var planet = 'rock!'; // (see variables)

// Arrays [bracket notation only]
['Don\'t', 'stop', 'the', planet][3]; // ???
['do', 'the', 'conga'][3] = 'beat'; // ???

// Objects
> { }['first'] = 'Gloria'; // ???
> { first: 'Gloria' }.last = 'Estefan'; // ???
> { music: 'is gonna get you!' }['music']; // ???

Just a quick intro, more on these later.

JavaScript Memory

"rock!"

"rock!"

{ "first":"Gloria" }

['do', 'the', 'conga', 'beat']

"is gonna get you!"

{ 
  "first":"Gloria",
  "last":"Estefan" 
}

Oh wait, I need to use that again

'Stevie Nicks'

'Edge of Seventeen'

001

002

Slot

JavaScript Memory

// Proper Declaration
> var name = 'Stevie Nicks'; 
> var song = 'Edge of Seventeen'; 

// Don't use (for now)
> window.newerName = 'Charlie Parker';
> window.newerSong = 'Early in the Morning';

// NEVER USE
> newName = 'Eddie Money';
> newSong = 'Take me home tonight';

Bad convention: 'new___'

// Declare and assign at the top of your scope/code
2 > var favBand = 'Earth Wind and Fire';
3 > var favSong = 'Fantasy';
4 >
5 > console.log(favBand, favSong);

// Good Examples (declarations only)
> var songsArray;     // Descriptive of the reference
> var artistName;     // Single word
> var templeOfTheDog; // 'camelCase': hungryHungryHungry

// Words not to use (your code will break):
// > var new, var, in, function, String, Number, break, typeof...
// Basically, If your editor highlights the word, don't use it!

// Bad Examples (declarations only)
> var SongTitles;  // Start with lowercase
> var tracknumber; // Use camelCase
> var newArray;    // Of what?
> var &no$yb@ls;   // Code will break

Use 'console.log' to check values

'David'

'Bowie'

001

002

Slot

JavaScript Memory

> firstNameAgain;

> var firstNameAgain = firstName;

// What is Javascript doing?
> firstName = 001;
> lastName = 002;

// Proper Declaration
> var firstName = 'David';
> var lastName = 'Bowie';

003

'David'

 = 003;

'StevieWonder'

'Stevie Wonder'

'Stevie'

'Wonder'

// Proper Declaration
> var firstName = 'Stevie';
> var lastName = 'Wonder';

// We want his full Name
> firstName + lastName; 
// 'Stevie' + 'Wonder'

// Fix the formatting
> firstName + ' ' + lastName; 
// 'Stevie' + ' ' + 'Wonder'

JavaScript Memory

Reference Error

// Print the fullName
console.log(fullName); // ???

Slot

JavaScript Memory

JavaScript Console

'Scott Weiland'

'Scott'

JavaScript Memory

undefined

'Scott Weiland'

'Scott'

JavaScript Console

'Scott Weiland'

Makes a copy for 'primitive' types.

// Declare before using
> var fullName = 'Scott Weiland';
> var firstName = fullName.split(' ')[0];

> console.log(fullName); // ???
> console.log(firstName); // ???

34 // What's gonna happen?
35 > console.log(stoneTemplePilots); // ???
36 > var stoneTemplePilots = fullName; // ???

// Overwriting
> fullName = 'Stone Temple Pilots'; // ???
> console.log(fullName); // ???

'Declared' or 'namespaced' but not 'defined' before it's used. Hence 'undefined'

001

002

Slot

003

// 001

// 002

'Stone Temple Pilots'

004

'Stone Temple Pilots'

// 004

// 003

// 001

// 002

// 004