Introduction to JavaScript (part1)

What is JavaScript ?

JavaScript is a lightweight, interpreted programming language.

What is JavaScript ?

JavaScript is a lightweight, interpreted programming language.

Advantages
Less server

What is JavaScript ?

JavaScript is a lightweight, interpreted programming language.

Advantages
Less server

JavaScript Where To

The

JavaScript Where To

The
JavaScript in

JavaScript Where To

The
JavaScript in

External JavaScript

External JavaScript

Advantages:
It separates HTML and code.
It makes HTML and

JavaScript Syntax

Comments:
// var x = 5 + 6; I will not

JavaScript Display Possibilities

Writing into the HTML output using document.write().
Writing into an

JavaScript Display Possibilities

Writing into the HTML output using document.write().
Writing into an

JavaScript Statements

Click to ad text

Numbers are

Click to ad text

Numbers are

JavaScript Identifiers

All JavaScript variables (and JavaScript functions) must be identified with

JavaScript Identifiers

All JavaScript variables (and JavaScript functions) must be identified with

JavaScript Identifiers

All JavaScript variables (and JavaScript functions) must be identified with

JavaScript Identifiers

All JavaScript variables (and JavaScript functions) must be identified with

Declaring (Creating) JavaScript Variables

var carName;
//Variable declared without a value will

Global variables are evil!!!!

evil = 'Variable declaration without var'

JavaScript Keywords
(reserved words)

JavaScript Keywords
(reserved words)

var albums = 16; // Number assigned by a number literal
var

JavaScript Data Types

Number:
Integer
Float
Infinity
NaN

String:
“text1”
‘text2’

Boolean:
true
false

Object:
object
null
Array
Function

undefined

The typeof Operator

typeof "Cat"

The typeof Operator

typeof "Cat" // Returns string
typeof 3.14

The typeof Operator

typeof "Cat" // Returns string
typeof 3.14 // Returns number
typeof

The typeof Operator

typeof "Cat" // Returns string
typeof 3.14 // Returns number
typeof

The typeof Operator

typeof "Cat" // Returns string
typeof 3.14 // Returns number
typeof

The typeof Operator

typeof "Cat" // Returns string
typeof 3.14 // Returns number
typeof

Strings

Length:
var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var sln = txt.length;

Strings

Length:
var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var sln = txt.length;

Special Characters:

* escape character \

Strings

Created from literals:
var x = "Lorem ipsum";

Strings

Created from literals:
var x = "Lorem ipsum";
Defined as objects:
var y =

Strings

Created from literals:
var x = "Lorem ipsum";
Defined as objects:
var y =

Strings

Created from literals:
var x = "Lorem ipsum";
Defined as objects:
var y =

String Methods

String Methods

String Methods

Finding a String in a String:
indexOf()
var str = "The

String Methods

Finding a String in a String:
indexOf()
var str = "The

String Methods

Finding a String in a String:
indexOf()
var str = "The

String Methods

Finding a String in a String:
indexOf()
var str = "The

String Methods

Extracting String Parts:
slice(start [, end])
var str = "The

String Methods

Extracting String Parts:
slice(start [, end])
var str = "The

String Methods

Extracting String Parts:
slice(start [, end])
var str = "The

String Methods

Replacing String Content:
replace(regexp|substr, newSubStr|function)
str = "One coffee, please!";
var

String Methods

Replacing String Content:
replace(regexp|substr, newSubStr|function)
str = "One coffee, please!";
var n

String Methods

concat(string1, string2, ..., stringX)
The concat() method can be used instead

Numbers

By default, Javascript displays numbers as base 10 decimals.
Base 16 (hex),

Numbers

Infinity
// Execute until Infinity

or
var x = 2 / 0;

Numbers

Infinity
// Execute until Infinity

or
var x = 2 / 0;
NaN - Not a Number
var x = 100 / "Apple";
var x = 100 / "10";
isNaN(x); // returns true because x is Not a Number

Numbers

Created from literals:
var x = 123;

Numbers

Created from literals:
var x = 123;
Defined as objects:
var y = new

Numbers

Created from literals:
var x = 123;
Defined as objects:
var y = new

Numbers

Created from literals:
var x = 123;
Defined as objects:
var y = new

Global methods for numbers

Try:
x = true;
Number(x);
x = false;
Number(x);
x =

Number methods

toString()
var x = 123;
x.toString(); // returns 123 from variable x
(123).toString();

Number methods

toString()
var x = 123;
x.toString(); // returns 123 from variable x
(123).toString();

Number methods

toString()
var x = 123;
x.toString(); // returns 123 from variable x
(123).toString();

Booleans

Everything With a Real Value is True:
Boolean(100);
Boolean(3.14);
Boolean(-15);
Boolean("Hello");
Boolean('false');
Boolean(1 + 7 + 3.14);

Booleans

Everything With a Real Value is True:
Boolean(100);
Boolean(3.14);
Boolean(-15);
Boolean("Hello");
Boolean('false');
Boolean(1 + 7 + 3.14);

Everything

Arrays

JavaScript arrays are used to store multiple values in a single

Arrays

JavaScript arrays are used to store multiple values in a single

Arrays

JavaScript arrays are used to store multiple values in a single

Arrays

Avoid new Array()!
Try:
var points = new Array(40, 100);
var points =

Arrays

Avoid new Array()!
Try:
var points = new Array(40, 100);
var points =

Arrays

Avoid new Array()!
Try:
var points = new Array(40, 100);
var points =

Array Methods

Converting Arrays to Strings
var fruits = ["Banana", "Orange", "Apple", "Mango"];
valueOf()
document.getElementById("demo").innerHTML

Array Methods

Converting Arrays to Strings
var fruits = ["Banana", "Orange", "Apple", "Mango"];
valueOf()
document.getElementById("demo").innerHTML

Array Methods

Converting Arrays to Strings
var fruits = ["Banana", "Orange", "Apple", "Mango"];
valueOf()
document.getElementById("demo").innerHTML

Array Methods

Add and remove elements
var fruits = ["Banana", "Orange","Apple", "Mango"];
pop() removes

Array Methods

Add and remove elements
var fruits = ["Banana", "Orange","Apple", "Mango"];
pop() removes

Array Methods

Add and remove elements
var fruits = ["Banana", "Orange","Apple", "Mango"];
pop() removes

Array Methods

Add and remove elements
var fruits = ["Banana", "Orange","Apple", "Mango"];
pop() removes

Array Methods

Add and remove elements
var fruits = ["Banana", "Orange","Apple", "Mango"];
splice(index[, deleteCount,

Array Methods

var fruits = ["Banana", "Orange","Apple", "Mango"];
sort()
fruits.sort();
reverse()
fruits.reverse();

Objects

Hobbit

Objects

Hobbit
Hobbit.name = “Bilbo”
Hobbit.age = 132
Hobbit.address = Shire
Hobbit.hair = true

Hobbit.walk()
Hobbit.fight()
Hobbit.keepRing()

Objects

Hobbit
Hobbit.name = “Bilbo”
Hobbit.age = 132
Hobbit.address = Shire
Hobbit.hair = true

Gollum

Hobbit.walk()
Hobbit.fight()
Hobbit.keepRing()

Objects

Hobbit
Hobbit.name = “Bilbo”
Hobbit.age = 132
Hobbit.address = Shire
Hobbit.hair = true

Gollum
gollum = new

Objects

All hobbits have the same properties, but the property values differ

Objects

All hobbits have the same properties, but the property values differ

Objects

var х = lastName;
console.log(person.firstName);
console.log(person[х]);
person.walk();