{Objects}
[Arrays]
Function(s){}

slides:  bit.ly/js102-slides1

exercises: bit.ly/js102-exercises

 

Who is this for?

2-6mos experience learning JavaScript

Completed JS tutorial like Codecademy, CodeSchool, Khan Academy, or Bloc.io

Want to solidify fundamentals

Looking for more practice

Interested in getting into Telegraph Academy

Part 1

Review and solidify core JS principles with project.

Part 2

Get started with functional methods. 

After

Use foundation to grow as a JS engineer.

Telegraph Prep

Objects
 

{}

OVERVIEW

  1. Property Access
  2. Bracket Notation
  3. Dot Notation
  4. Dot vs Bracket
  5. Nested Objects
  6. Object Literals
  7. Iteration

 

var box = {};

Data

 

var box = {};
						
box.material = "cardboard";

Assignment w/ Dots

When are some other times you have seen dots in JS?
var box = 
{"material" : "cardboard"}

 

var box = {};
						
box.material = "cardboard";						
						
box.material; //??

Assignment w/ Dots

var box = 
{"material" : "cardboard"}

 

var box = {};
						
box.material = "cardboard";
						
var cb = box.material;

Access w/ Dots

var box = 
{"material" : "cardboard"}

Access w/ Dots

box = 
{"material" : "cardboard"}
var box = {};
    					
box.material = "cardboard";
						
var cb = box.material;

cb; //??

box.material = "titanium";

cb; //??
box = 
{"material" : "titanium"}
cb = "cardboard"

 

var box = {};
						
box.material = "cardboard";
						
box.material; //"cardboard"
						
box.size; //??

Access and Assignment

var box = 
{"material" : "cardboard"}

 

var box = {};
						
box["material"] = "cardboard";
						
box.material; //??

Brackets

var box = 
{"material" : "cardboard"}

 

var box = {};
						
box["material"] = "cardboard";
						
box["material"]; //??

Brackets

var box = 
{"material" : "cardboard"}

 

var box = {};
						
box["material"] = "cardboard";
						
						
var key = "material";
						
box[key]; //??

Variables

 

var box = {};
						
box["material"] = "cardboard";
						
var func = function(){
 return "material";
};
						
box[func()]; //??

Expressions

 

var box = {};
						
						
box['material'] = "cardboard";
						
var key = 'material';
						
						
box['key']; //??

 

var box = {};
						
						
box['material'] = "cardboard";
						
var key = 'material';
						
						
box['key']; //undefined
box.key; //??

 

 

 

 

var box = {};
						
						
box['material'] = "cardboard";
						
var key = 'material';
						
						
box['key']; //undefined
box.key; //undefined

 

var box = {};
						
						
box['material'] = "cardboard";
						
var key = 'material';
						
						
box['key']; //undefined
box.key; //undefined						
box[key]; //??

 

 

var box = {};
						
						
box['material'] = "cardboard";
						
var key = 'material';
						
						
box['key']; //undefined
box.key; //undefined						
box[key]; //"cardboard"

 

Do's && Don'ts

 

var box = {};
						
box['material'] = "cardboard";
box[0] = 'meow';
box['^&*'] = "testing 123";

var test = box['^&*'];

non-valid characters

box = 
{"material" : "cardboard",
 "0" : "meow",
 "^&*" : "testing 123"
}

THE RULES

DOTS

​strings

Brackets

​strings"

"quotes required

weird characters"
variables
numbers
numbers
quotations
weird characters
expressions
expressions

Storing Data

 

var box = {};
						
box["material"] = "cardboard";
						
box["size"] = {
  "height": 2,
  "width": 80
};

box.area = function(){
  return box.size.height * box.size.width;
};

Style: Bracket vs. Dots

 

var box = {};
						
box['size'] = 9;
						
box['~/ [."4'] = 'meow';
						
						
box['size']; // 9
						
box['~/ [."4']; // 'meow'

Object Literals

 

var box = {
						
box['size'] = 9;
						
box['~/ [."4'] = 'meow';};						box['size']; // 9
						
box['~/ [."4']; // 'meow'

 

var box = {
						
box['size'] = 9;
						
box['~/ [."4'] = 'meow';};						box['size']; // 9
						
box['~/ [."4']; // 'meow'

 

var box = {
						
    'size'  = 9;
						
    '~/ [."4'  = 'meow';};						box['size']; // 9
						
box['~/ [."4']; // 'meow'

 

var box = {
						
    'size'  : 9,
						
    '~/ [."4'  : 'meow';};						box['size']; // 9
						
box['~/ [."4']; // 'meow'

 

var box = {
						
    'size'  : 9,
						
    '~/ [."4'  : 'meow'};						box['size']; // 9
						
box['~/ [."4']; // 'meow'

Iteration

 

var box = {};
						
box['material'] = "cardboard";						
box[0] = 'meow';
box['^&*'] = "testing 123";


for(var key in box){
  console.log(key); //?? 
}

 

var box = {};
						
box['material'] = "cardboard";						
box[0] = 'meow';
box['^&*'] = "testing 123";


for(var key in box){
  console.log(box[key]); //?? 
}

Iteration

Exercise Time

What is an object? 

 What is the difference between dot and bracket notation?

When can you only use brackets and not dot?

When can you only use dot notation and not bracket? 

How do you add a property with a key that contains special characters?

 How do you add a property with a key that is stored in a variable? 

How do you add a property whose key and value are stored in different variables?

How do you access an object that is inside another object?

How do you create an object that is nested inside another object?

How do we loop through objects to access the values?

Arrays

[]

Overview

  • Arrays vs Objects
  • Access && Assignment
  • Native Methods && Properties
  • Iteration

Arrays vs Objects

 

var box = [];
						
box[0] = true;						
box[1] = 'meow';
box.push({'hello' : 'goodbye'});
						
						
var i = 0;
						
box[i]; // ??
box[1];
box.pop() //??

Access & Assignment

[true, 'meow', {'hello' : 'goodbye'}]

 index# 0         1              2

{0 : 'meow', 'size' : 9 }

 

var box = {};
						
box['size'] = 9;
						
box['0'] = 'meow';
						
						
box['size']; // 9
						
box[0]; // 'meow'

Access & Assignment

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
						
box['size']; // ??
						
box[0]; // ??

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
						
box.size; // ??
						
box[0]; // ??

Access & Assignment

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

The Rules Don't Change!

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
						
box.size; // ??
						
box.0; // ??

Access & Assignment

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
for(var k in box){
						
  console.log(k); // ??
						
}

Iteration

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
						
for(var k in box){
						
  console.log(box.k); // ??
						
}

Iteration

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;
						
box['0'] = 'meow';
						
for(var k in box){
  console.log(box[k]); //??
					
}

Iteration

['meow']

               index #        0

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;				
box['0'] = 'meow';				
box.push('Whoohoo!');
						
for(var k in box){					
  console.log(box[k]);				
}
						
for(var i = 0; i < box.length; i++){
						
  console.log(i); //??
						
}

Iteration

['meow', 'Whoohooo!']

     index #        0              1

{0 : 'meow', 1 : 'Whoohooo!', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;				
box['0'] = 'meow';				
box.push('Whoohoo!');

						
for(var i = 0; i < box.length; i++){
						
  console.log(box.i); //??
						
}

Iteration

['meow', 'Whoohooo!']

     index #        0              1

{0 : 'meow', 1 : 'Whoohooo!', 'size' : 9 }

 

var box = [];
						
box['size'] = 9;				
box['0'] = 'meow';				
box.push('Whoohoo!');

						
for(var i = 0; i < box.length; i++){
						
  console.log(box[i]); //??
						
}

Iteration

['meow', 'Whoohooo!']

     index #        0              1

{0 : 'meow', 1 : 'Whoohooo!', 'size' : 9 }

 

var box = [];
						
box['size'] = true;
						
box['0'] = 'meow';
						
						

						
box.length; //??

Native Properties

['meow']

     index #                   0              

{0 : 'meow', 'size' : 9 }

 

var box = [];
						
box['0'] = 'meow';
box[3] = {'babyBox': true}; 
						
						

						
box['length']; //??

Native Properties

 

var box = [];
						
						
box['0'] = 'meow';

box[3] = {'babyBox': true};
						
						

						
box[length]; //??

Native Properties

 

var box = [];
						
box['0'] = 'meow';						
box[1] = 'Whoohooo!';
box[3] = {'babyBox': true};

						

									
box[box.length]; //??

Native Properties

 

var box = [];	
					
box['size'] = 9;				
box['0'] = 'meow';
box[1] = 'Whoohooo!';
						
						
						
box[box.length - 1]; //??

Native Properties

['meow', 'Whoohooo!']

     index #        0              1

{0 : 'meow', 1 : 'Whoohooo!', 'size' : 9 }

 

var box = [];	
				
box['0'] = 'meow';
box[1] = 'Whoohooo!';
						
						
						
box[box.length - 1]; //??

Native Methods

['meow', 'Whoohooo!']

     index #        0              1

         {0 : 'meow', 1: 'Whoohooo!'}

 

var box = {};
						
box.innerBox = {};

Nesting

var box = 
{"innerBox" : {}}

 

var box = {};
						
box['innerBox'] = {};

Nesting

var box = 
{"innerBox" : {}}

 

var box = {};
						
box['innerBox'] = {};
						
box['innerBox']['full'] = true;

Nesting

var box = 
{"innerBox" : {
    full: true
  }
}

 

var box = {};
						
box['innerBox'] = {};
						
box['innerBox'].full = true;

Nesting

var box = 
{"innerBox" : {
    full: true
  }
}

 

var box = {};
						
box.innerBox = {};
						
box.innerBox.full = true;
						
						
box.innerBox; //??

Nesting

var box = 
{"innerBox" : {
    full: true
  }
}

 

var box = {};
						
box.innerBox = {};
						
box.innerBox.full = true;
						
						
var myInnerBox = box.innerBox;
						
myInnerBox; //??

Nesting

var box = 
{"innerBox" : {
    full: true
  }
}

 

var box = {};
						
box.innerBox = {};
						
box.innerBox.babyBox = {};
						
						
box.innerBox['babyBox']; //??
						
box.innerBox['babyBox'].says = "What's up!?";

Nesting

var box = 
{"innerBox" : {
    babyBox : {
      says: "What's up!?"
    }
  }
}

 

var box = {};
						
box['innerBox'] = {};					
box['innerBox'].full = true;
						
						
box[innerBox]['height'] = 10;
						

					
box[innerBox2].full = false;

Nesting

Exercise Time

What do you use to loop through an array?

What are some different methods of adding values to an array?

What are some special properties about arrays that are different from objects?

What are some ways to access values in your array?

When would you use an array over an object?

Functions

function(){}

Overview

  • Anatomy

Anatomy

Definition

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

Name

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

Body

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

Invocation/Call-time

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

Arguments/Parameters

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

return/side effects

var nameImprover = function (name, adj) {
  return 'Col ' + name + ' Mc' + adj + ' pants';
};

$('body').hide();

myArr.forEach(function(val){ console.log(val);});

$('button').on('click', function(){ 
  console.log('Don\'t press my buttons!');
});

Quick Review

var add = function(a, b){
     return a + b;
};
add(3, 4, 5); // ??

add(4, 10, 3); //13?

arguments Keyword

var add = function(a, b){
    console.log(arguments); //logs [3,10,5]
 	return a + b; 
};
add(3, 10, 5); //13

arguments Keyword

var add = function(a, b){
    console.log(arguments); //logs [3,10,5]
 	return a + b; 
};
add(3, 10, 5); //18??

array-like object

var add = function(a, b){
  arguments.slice(0,1) //ERROR!!  
  return a + b; 
};
add(3, 10, 5);

P.S. Functions are

Objects!

var add = function(a, b){
 	return a + b; 
};
add.example = 'testing 123!';

Exercise time

Questions

function AnimalMaker(name) {
  return { 
    speak: function () { 
      console.log("my name is ", name); 
    } 
  };
};
    
var animalNames = ['Sheep', 'Liger', 'Big Bird'];

Looping

function AnimalMaker(name) {
  return { 
    speak: function () { 
      console.log("my name is ", name); 
    } 
  };
};
    
var animalNames = ['Sheep', 'Liger', 'Big Bird'];  

var farm = [];

Looping

function AnimalMaker(name) {
  return { 
    speak: function () { 
      console.log("my name is ", name); 
    } 
  };
};
    
var animalNames = ['Sheep', 'Liger', 'Big Bird'];  

var farm = [];

for(var i = 0; i < animalNames.length; i++){
  var animal = AnimalMaker(animalNames[i])
  farm.push(animal);
}

Looping

function AnimalMaker(name) {
  return { 
    speak: function () { 
      console.log("my name is ", name); 
    } 
  };
};

var animalNames = ['', '', ''];
var farm = [];

for(var i = 0; i < animalNames.length; i++){

  farm.push(AnimalMaker(animalNames[i]));
  //prev 2 lines condensed onto one
}

Looping

function AnimalMaker(name) {
  return { 
    speak: function () { 
      console.log("my name is ", name); 
    }
  };
};

var animalNames = ['Sheep', 'Liger', 'Big Bird'];

var farm = [];

for(var i = 0; i < animalNames.length; i++){
  farm.push(AnimalMaker(animalNames[i]));
}

for(var j = 0; j < farm.length; j++){
  farm[j].speak()
}

Looping

Exercises

Scope

Overview

  • Local
  • Global
  • Nested Scopes
  • Precedence
  • Block Scope

Local Scope

var func = function(){
  var local = true;
};

console.log(local);
var x = 'global!';
var x = 'global!';

//inside a function
function encapsulate(){

z = 'global here, too!';

}
var x = 'global!';

//inside a function
function encapsulate(){
  z = 'global here, too!';

  window.y = 'also global!';
}

Global Scope

Parent vs Child Scope

var g = 'global'; 

function blender(fruit) { 
  var b = fruit; 
  var y = 'yogurt';
 
  function bs() { 
    alert( b + ' and ' + y + ' makes ' + b + ' swirl'); 
  } 
  bs(); 
} 

blender('blueberry');

Privacy

var g = 'global'; 

function blender(fruit) { 
  var b = fruit; 
  var y = 'yogurt';
 
  function bs() { 
    alert( b + ' and ' + y + ' makes ' + b + ' swirl'); 
  } 
  bs(); 
} 

blender('blueberry');

creating scopes

Precedence

var g = "global";

function go() { 
  var l = "local";
  var g = "in here!";
  alert(g + " inside go");
}

go();
alert(g + " outside go");

Block Scope

var inBlock = false;

for(var i = 0; i < 5; i++){
  var inBlock = true;
};

if(inBlock){
  console.log('Is there block scope? ' + !inBlock);
}

Exercise Time

Questions

Part 1
is
complete!

 

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