JavaScript JumpStart

Schedule

Lecture 1: 9:45 - 10:45
- Workshop 1: 10:45 - 12:30
- Review: 12:30 - 1:00
Lunch: 1:00 - 2:00
Lecture 2: 2:00 - 2:30
- Workshop 2: 2:30 - 4:30
- Review 4:30 - 5:00
Lecture 3: 5:00 - 5:30
- Workshop 3: 5:30 - ?
Closing Comments

What will we cover? (content)

JavaScript Fundamentals

Values, Types and Operators
Program Structure
Functions
Data Structures
- Arrays

JumpStart Lecture
One

JavaScript Value Types

Numbers
Strings
Booleans
Objects
- Functions, Arrays
Null
Undefined

var oneDozen = 12;

var myName = "Scott"

var theSkyIsBlue = true

var macBook = {
  model: "2014 Air",
  price: 1400
}

null

undefined;

Topics and Concepts

Defining Variables
Value Types
- Numbers
- Strings
- Booleans
- Functions
Arithmetic Operators
Comparators
Logical Operators
Program Structure
- If Statements
- Loops

Variables

How does a program remember things?
- To catch and hold values JavaScript provides variables

var one = 1;

var

The "var" keyword indicates the definition of a local variable

var one

"var" is followed by the name of the variable

var one = 1;

The name is followed by the assignment operator and an expression or value

Variables

Think of a Variable like a Label on a Box

Variables

Declaration: Creating an empty variable
- Putting a label on it
Initialization: Assigning a value to the variable

Why use a Variable?

Easily Identifiable
Reuse throughout your application without unnecessarily duplicating the value itself.

Variables

Naming Conventions
- Letters
- Digits
- Underscores
- Dollar Signs
- Must begin with a letter, underscore or dollar sign
- Case Sensitive
- Reserved Words cannot be used as a variable name
- CamelCase

var t3l_lo$ = "valid";

var 2invalid = "invalid";

var camelCase = "camelCase";

var var = "invalid";

var CaSeSeNsItIvE = "valid";

Variables

var one = 1;
var two = one + one;

var two = 2

var one = 1;
var two = one + one;
one = one + two;

var one = 3

What is a Function?

A function is similar to a baking recipe such as baking a cake
The "values" or ingredients used changes the type of cake, but the outcome is still a cake.
- Ex: What ingredients are different between a Chocolate or Vanilla Cake?

function bakeCake(flavor){
  return "This is a " + flavor + "cake!";
}

bakeCake("Chocolate");

bakeCake("Vanilla");

Functions

A function is a block of reusable code.
Executing a function is called invoking, calling, or applying it.
Values inside the parentheses are passed to the program inside the function.
Groups statements together

Functions

alert("My Name Is Scott");

This is a JavaScript Statement that invokes the alert function which accepts a string value argument

Functions

// function declaration
function alertTwoTimes(message){
  alert("First Message: " + message);
  alert("Second Message: " + message);
}
alertTwoTimes("Hello"); //invoking the function

function keyword: tells the JavaScript engine to treat the block of code as a function
name: after the function keyword is the name of the function (distance)
parentheses: inside the parentheses are the parameters(the values passed to the function are arguments), Order Matters
brackets: opening and closing squiggly brackets enclose any statements that you have inside
content: the statements that are invoked
calling: after the function is created it has to be called.

Booleans

1 of the 6 Types in JavaScript
Two Possibilities:
- True
- False

Conditional Statements

During your morning routine you make a series of decisions in a conditional format.
- If it is cold out you will wear a jacket
- If you are hungry you will have breakfast
- If you are running late you will move faster
IF/ELSE Statement:

if(something_is_true){
  // do_something;
} else {
  // nothing is true
  // run this code
}

If/Else Example

function whichBrowser(browser){
    if(browser === "Google Chrome"){
        alert("This is Google Chrome!");
    } else {
        alert("Download Chrome!");
    }
}
whichBrowser("Google Chrome");

The "return" Keyword

The "return" keyword gives back data from a function.
When the "return" keyword is used, anything after the return keyword will not execute.

function returnValue(valueToReturn){
  return valueToReturn;
}
returnValue("JavaScript Rocks");

function exampleReturn(expression){
  if(expression){
    return "The expression is true";
  } else {
    return "The expression is false";
  }
  console.log(5);
}
exampleReturn(11<10);

Conditional Operators

Compare between two or more things
The end goal is to return 'true' or 'false' so that our 'if statement' knows which block of code to execute
Basic Conditional Operators
- " > ": Greater Than
- " < ": Less Than
- " >= ": Greater Than or Equal To
- " <= ": Less Than or Equal To
- " === ": Equal To (Identity Operator)
- " !== ": Not Equal To

if(7 < 10){
  console.log("7 is less than 10");
} else {
  console.log("7 is greater than 10");
}

"else if" Statement Example

function isBakersDozen(guess){
    if(guess === 13){
        return "You are Correct";
    } else if(guess === 12){
        return "Close! But wrong Dozen";
    } else {
        return "Try Again";
    }
}

Adds more than one option to your program
Checks from Top to Bottom
Statements can be nested

Logical Operators

Typically used with Boolean Values
3 Logical Operators
- " && " : AND
  - Both Conditions must be true
- " || " : OR
  - One Condition must be true
- " ! " : NOT
  - Toggles a Statement from true to false or from false to true

true && true  // returns true

false || true // returns true

!false || !true // returns true

Numbers

Addition
Subtraction
Multiplication
Division
Modulus

var oneDozen = 12;
var twoDozens = 2 * oneDozen;

Common Arithmetic Operators in JavaScript

function add(num1, num2){
    return num1+num2;
}
add(5,6);

function modulo(num1,num2){
    return num1%num2;
}
modulo(11,5);

Shorthand Syntax(Operators)

Declare a Variable and initialize a value

var one = 1;

Add 1 to the variable one

one = one + 1;

Shorthand

one++;

one--;
one+=5;
one -=5;
one *= 2;
one /= 2;
one %= 3;

Strings

String: A series of characters enclosed by an apostrophe ( ' ) or quotation marks ( " )
Concatenation: Combines strings together

var jump = "Jump";
var start = 'Start';

var currentClass = jump + start;

String Properties

Properties enable interaction with a value and are pre-defined.
Methods are similar to properties except they are functions called on a value
Access Characters with bracket notation

function whatCharacter(stringToCheck,indexInString){
    return stringToCheck[char];
}
whatCharacter("HelloWorld",5);

var helloWorld = "Hello World";
helloWorld.length;

helloWorld.charAt(4);

Common String Properties

and Methods

"hello world".length;

.length property: returns the length of the string starting from the count of 1

"hello world".toUpperCase();

.toUpperCase method: returns the calling string value converted to upper case characters

.toString method: converts a value to a string value

var two = 22;
two.toString();

Accessing Individual Characters

Strings look like one cohesive unit but they are actually made up of a series of characters

Zero-Based Index (the count starts from 0 instead of 1)

Index positions start at 0 and then move up

var hello = "Hello";

Accessing Individual Characters

"Hello Fullstack".charAt(8);

"Hello Fullstack"[4];

charAt method: returns a character at a specified (the arguments) index value

Bracket Notation: returns the character at the specified index value.

"Hello Fullstack"[2+2];

"hello world".slice(2,5);

.slice method: returns a string based on the start and end point specified by the first and second argument

Common String Methods

.indexOf method: the arg is the substring or character to search for in the string. The return value is the index location of character or string

"Hello World".indexOf("World");

Strings

Special Characters
- \t - Tab Spacing
- \n - New Line
String Comparisons

"Hello\t\tWorld";

"Hello\n\nWorld";

"HelloWorld" === "HelloWorld";

Tab Spacing

New Line

Comparison

Loops

A generalized solution for repeating code with control over how many times the code is repeated
3 Different Loops
- for...
- while...
- do...while

doSomething();
doSomething();
doSomething();
doSomething();
doSomething();
doSomething();
doSomething();
doSomething();

var count = 8;
for(var i = 0; i < count; i++){
  doSomething();
}

var count = 10;
while(count > 0){
  count--;
  doSomething();
}

While-Loop

console.log("Repeat this #" + number + " 4 times");

Loops allow code to be executed repeatedly.

Define a Variable

var number = 1;

Create a counter to increase on every repetition of the loop

console.log("Repeat this #" + number + " 4 times");
number++;

Create an expression that evaluates to true or false

number <= 4;

While-Loop

var number = 1;
while(number <= 4){
  console.log("Repeat this #" + number + " four times");
  number++;
}

For - Loop

START/INITIALIZE: Create a variable ex: var i = 0;
EXPRESSION: Create an Expression ex: i < 10;
DO AFTER: Change the initial variable ex: i++

For - Loop

Initialize Counter
Evaluate Expression
Run Code
Increment Counter
Evaluate Expression

for(var i = 0; i < 10; i++){
  console.log(i);
}

For-Loop

function upToFive(){
  for(var i = 1; i<5; i++){
    console.log(5);
  }
}
upToFive();

JavaScript JumpStart

Schedule

JumpStart Lecture One

JavaScript Value Types

Topics and Concepts

Variables

Variables

Variables

Why use a Variable?

Variables

Variables

What is a Function?

Functions

Functions

Functions

Functions

Booleans

Conditional Statements

If/Else Example

The "return" Keyword

Conditional Operators

"else if" Statement Example

Logical Operators

Numbers

Shorthand Syntax(Operators)

Strings

String Properties

Common String Properties

and Methods

Accessing Individual Characters

Accessing Individual Characters

Common String Methods

Strings

Loops

While-Loop

While-Loop

While-Loop

For - Loop

For - Loop

For-Loop

Time for the Workshop!

JumpStart Lecture
One

Time
for the
Workshop!