• JavaScript Functions & Event Handlers

    JavaScript Functions & Event Handlers 

     

    JavaScript Functions

    ·         JavaScript function  is a section of code perform a specific task That When called. Calling a function is achieved by its name.

     

    The Unchained Tour offers the best Java training, and if you’re from Chennai make sure to check them out for your Java requirements

    Syntax:

    function function_name ()

      {

        function code

      }

    example:

    <Html>

    <Head>

    <Script>

    function helloFunction ()

    {

    alert ("Hello people!");

    }

    </ Script>

    </ Head>

    <Body>

    <button onclick = "helloFunction ()"> Press button </ button>

    </ Body>

    </ Html>

     

    Calling the Function:

    <script type = "text / javascript">

    <! -

    helloFunction ();

    // ->

    </ Script>

    Function with Parameters:

    <script type = "text / javascript">

    <! -

    function cityFunction (city, code)

    {

       alert (city + "city code is:" + code);

    }

    // ->

    </ Script>

    Calling the Function with Parameters:

    <script type = "text / javascript">

    <! -

    cityFunction ('London', 5);

    // ->

    </ Script>

    Function with a Return value:

    <script type = "text / javascript">

    <! -

    function fullname (firstname, lastname)

    {

       var name;     

       name = firstname + lastname;

       return name;   

    }

    // ->

    </ Script>

    Calling the Function with Return:

    <script type = "text / javascript">

    <! -

       var thename = fullname ('Tom', 'Joe');

       alert (thename);

    // ->

    </ Script>

    JavaScript Events

    JavaScript Events

    function  is a section of code that performs a specific task when called. Calling a function is achieved by its name.

    Syntax:

    function function_name () 
      {
        function code
      }

    example:

    <Html>
    <Head>
    <Script>
    function helloFunction ()
    {
    alert ("Hello people!");
    }
    </ Script>
    </ Head>
    <Body>
    <input type = "button" onclick = "helloFunction ()" value = "Press button" />
    </ Body>     
    </ Html>

    result:

     

    JavaScript Event Handlers 

    Event handling is the action following the event, such as onClick, onMouseOver, onKeyUp. Drive or treating an event has a JavaScript function that will take over the tasks assigned to the event.

    Event

    Description

    onBlur

    Action that will be triggered when the element loses focus on.

    we change

    Action that will be automatically triggered when changing an item.

    onFocus

    Action that will be triggered by focusing on an element.

    onreset

    Action will be initiated when the reset button of a form is pressed.

    onSelect

    Action that will be triggered when selecting an item.

    onSubmit

    Will be initiated when the submit button of a form is pressed.

    onclick

    Action that will be triggered when you press left click on the mouse.

    onDblClick

    Action that will be triggered when you click on the left mouse button.

    onMouseDown

    Action that will be triggered when a mouse button is pressed.

    onMouseMove

    Action that will be triggered when the mouse cursor moves.

    onMouseOut

    Action that will be triggered when the mouse cursor moves outside or bounded.

    onMouseOver

    Action that will be triggered when the mouse pointer moves over an element or over the surface area.

    onMouseUp

    Action that will be triggered when the mouse button is released.

    onKeyDown

    Action that will be triggered when a key is pressed.

    onKeyPress

    Action that will be triggered when you press and release a key.

    onKeyUp

    Action that will be triggered when a key is released.

    onError

    Action that will be triggered after loading an image or failure of a document.

    onload

    Action that will be automatically triggered when loading a document.

    onUnload

    Action that will be automatically triggered when a document does not load.

     


  • Commentaires

    Aucun commentaire pour le moment

    Suivre le flux RSS des commentaires


    Ajouter un commentaire

    Nom / Pseudo :

    E-mail (facultatif) :

    Site Web (facultatif) :

    Commentaire :