JavaScript Why..What..How? Introduction

JavaScript Why..What..How? Mohammed Alhusban

Introduction (5 Mins) Simple Program: Printing a Line of Text in a Web Page (10 Mins) Prompt Dialogs: Obtaining User Input Dynamic Welcome Page Outline Why & What How

Why JavaScript? Enhances functionality and appearance of the web page. Client-side scripting Makes pages more dynamic and interactive Easy-to-use Built into web browsers and other applications Offering functions such as Form validation (JS can be used to validate data before it is submitted to a server. This saves the server from extra processing). JavaScript can be used to set and retrieve web cookies (A JavaScript can be used to store and retrieve information on the visitor's computer). Cool stuff like drop-down menus. Hide and show elements. Animation. JS

5 Websites That use JavaScript Animation Effectively!!

What is JS? JavaScript is a very popular scripting language on the internet. Cross Platforms. JavaScript language runs inmultiple environments and on many platforms. JavaScript is usually embedded directly into HTML pages. JavaScript is an interpreted language (means that scripts execute without preliminary compilation) Father of JS Brendan Eich

Before going any further One of the most important things to do when learning a new language is to master basic input and output which is why Welcome to has become almost a cliché in programming textbooks. Output Methods ,[object Object]

Windows.alert (ex.2)input Methods ,[object Object],[object Object]

Code: Ex.1 html opening tag Usually Java Scripts are included within the head tag, it also could be included in the body tag.

Code: Ex.1 html opening tag Usually Java Scripts are included within the head tag, it also could be included in the body tag. One reason JavaScript is so popular is that it's relatively easy to add JavaScript to a web page JavaScript Code block

Code: Ex.1 <script> tag: Indicate that the text is part of a script

Code: Ex.1 type attribute: Specifies the type of file and the scripting language use.

Code: Ex.1 <script> tag: Indicate that the text is part of a script type attribute: Specifies the type of file and the scripting language use. </script> End or Close Tag

Code: Ex.1 A Method used to output a string onto the Browser

Code: Ex.1 The string, that writeln method takes and printout on the browser. Whatever between the quotations mark will be printed as is. A Method used to output a string onto the Browser

Execute Ex.1: Output Run

Code: Ex.2 String will be printed out on the msg box or popup window Popup window

Execute Ex.2: Output

JavaScript Data Types and Variables Variable is a facility for storing data. The current value of the variable is the data actually stored in the variable. Variable in JavaScript has name and value Declare a variable  give it a name ( ex. var x ) Initialize a variable  give it a value ( ex. x = 100) In order to use variable, they must be declared and initialized. Variable types are not important in JavaScript. They may be interchanged as necessary. This means that if a variable is a string one minute, it can be an integer the next. Declare  initialize  Call

Code: Ex.3 Declaration of a variable

Code: Ex.3 You can declare JavaScript variables with the var statement What? Huh

Code: Ex.3 Initialization of the variable (name)

Code: Ex.3 Prompt window prints out the string between quotations

Code: Ex.3 writeln method prints the following in the browser: string + value of the variable name + string Hello + name value (input name) + Welcome to JavaScript Programming!

Next Lecture Learning to Love JavaScript Prototypes Thank you, I hope you have enjoyed this presentation

JavaScript Why..What..How? Introduction

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