Home
HTML
HTML Introduction HTML Tags HTML Elements HTML Attributes HTML Heading HTML Paragraph HTML Formatting HTML Quotations HTML Comments HTML Styles HTML Color HTML CSS HTML Images HTML Favicon HTML Links HTML DIV HTML Tables HTML Table Size HTML Table Head Table Padding & Spacing Table colspan rowspsn HTML Table Styling HTML Colgroup HTML List HTML Block & Inline HTML Classes HTML Id HTML Iframes HTML Head HTML Layout HTML Semantic Elements HTML Style Guide HTML Forms HTML Form Attribute HTML Form Element HTML input type HTML Computer code HTML Entity HTML Symbol HTML Emojis HTML Charset HTML Input Form Attribute HTML URL Encoding
CSS
CSS Introduction CSS Syntax CSS Selector How To Add CSS CSS Comments CSS Colors CSS Background color CSS background-image CSS Borders CSS Margins CSS Height, Width and Max-width CSS Box Model CSS Outline CSS Text CSS Fonts CSS Icon CSS Links CSS Tables CSS Display CSS Maximum Width CSS Position z-index Property
JavaScript
What is JavaScript JS Syntax JS Variables JS Data Types JS Operators JS Control Flow - IF JS Control Flow - Switch JS Control Flow - Loop JS Function JS Object Methods JS Anonymous Functions JS Recursive Function JS Default Parameters JS this Keyword
JQuery
What is jQuery? Benefits of using jQuery Include jQuery Selectors. Methods. The $ symbol and shorthand. Selecting elements Getting and setting content Adding and removing elements Modifying CSS and classes Binding and Unbinding events Common events: click, hover, focus, blur, etc Event delegation Using .on() for dynamic content Showing and hiding elements Fading elements in and out Sliding elements up and down .animate() Understanding AJAX .ajax() .load(), .get(), .post() Handling responses and errors. Parent Chlid Siblings Filtering Elements Using find Selecting form elements Getting form values Setting form values Form validation Handling form submissions jQuery plugins Sliders plugins $.each() $.trim() $.extend() Data attributes Debugging jQuery code
Bootstrap 4
What is Bootstrap Benefits of using Setting up Container Row and Column Grid Classes Breakpoints Offsetting Columns Column Ordering Basic Typography Text Alignment Text colors Backgrounds Display Font Size Utilities Buttons Navs and Navbar Forms Cards Alerts Badges Progress Bars Margin Padding Sizing Flexbox Dropdowns Modals Tooltips Popovers Collapse Carousel Images Tables Jumbotron Media Object
Git
Understanding Version Control Download and Install Git Git Configure Git Initialize Add Changes to Staging Commit Changes Branching Merging Remote Repository Understanding Git Conflicts Stashing Changes Viewing Commit History Undoing Changes
PHP
PHP Introduction PHP Installation PHP Syntax PHP Comments PHP Variable PHP Echo PHP Data Types PHP Strings PHP Constant PHP Maths PHP Number PHP Operators PHP if else & if else if PHP Switch PHP Loops PHP Functions PHP Array PHP OOps PHP Class & Object PHP Constructor PHP Destructor PHP Access Modfiers PHP Inheritance PHP Final Keyword PHP Class Constant PHP Abstract Class PHP Superglobals PHP Regular Expression PHP Interfaces PHP Static Method PHP Static Properties PHP Namespace PHP Iterable PHP Form Introduction PHP Form Validation PHP Complete Form PHP Date and Time PHP Include Files PHP - Files & I/O File Upload PHP Cookies PHP SESSION PHP Filters PHP Callback Functions PHP JSON PHP AND Exceptions PHP Connect database
MY SQL
SQL Introduction Syntax Select statement Select Distinct WHERE Clause Order By SQL AND Operator SQL OR Operator SQL NOT Operator SQL LIKE SQL IN SQL BETWEEN SQL INSERT INTO SQL NULL Values SQL UPDATE SQL DELETE SQL TOP, LIMIT, FETCH FIRST or ROWNUM Clause SQL MIN() and MAX() Functions SQL COUNT() Function SQL SUM() SQL AVG() SQL Aliases SQL JOIN SQL INNER JOIN SQL LEFT JOIN SQL RIGHT JOIN SQL FULL OUTER JOIN SQL Self Join SQL UNION SQL GROUP BY SQL HAVING SQL EXISTS SQL ANY and ALL SQL SELECT INTO SQL INSERT INTO SELECT SQL CASE SQL NULL Functions SQL Stored Procedures SQL Comments SQL Operators SQL CREATE DATABASE SQL DROP DATABASE SQL BACKUP DATABASE SQL CREATE TABLE SQL DROP TABLE SQL ALTER TABLE SQL Constraints SQL NOT NULL SQL UNIQUE Constraint SQL PRIMARY KEY SQL FOREIGN KEY SQL CHECK Constraint SQL CREATE INDEX SQL AUTO INCREMENT SQL Dates SQL Views SQL Injection SQL Hosting SQL Data Types

Binding and unbinding events

In jQuery, event binding and unbinding are mechanisms to attach event handlers to elements on a webpage and subsequently remove them when no longer needed. Here’s a breakdown:

Event Binding

Binding an event in jQuery involves attaching an event handler function to one or more selected elements. This allows you to specify what should happen when a particular event (like clicking a button, hovering over an element, etc.) occurs. The general syntax for binding an event handler is:

$(selector).on(event, childSelector, data, function)

selector: Specifies the element(s) to which the event handler should be attached.
event: Specifies the event or events to listen for (e.g., 'click', 'mouseover', etc.).
childSelector (optional): A selector string to filter child elements that trigger the event.
data (optional): Data to be passed to the event handler.
function: The function to execute when the event is triggered.

For example, to bind a click event to all <button> elements:

$('button').on('click', function() {
    console.log('Button clicked!');
});

Event Unbinding

Unbinding removes previously attached event handlers from elements. This is useful when you no longer want an event to trigger a particular function or when elements are removed dynamically from the DOM. The syntax for unbinding events is:

$(selector).off(event, childSelector, function)

selector: Specifies the element(s) from which the event handler should be removed.
event: Specifies the event or events from which to remove the handler.
childSelector (optional): A selector string to filter child elements.
function (optional): The specific event handler function to remove.

For example, to unbind a click event handler from all <button> elements:

$('button').off('click');

Example Use Case

Let's say you have a button that toggles a modal dialog. You can bind the click event to show the modal and unbind it when the modal is closed or no longer needed:

// Binding the click event to show the modal
$('#openModalButton').on('click', function() {
    $('#myModal').show();
});

// Unbinding the click event when the modal is closed
$('#myModal .close').on('click', function() {
    $('#myModal').hide();
    $('#openModalButton').off('click'); // Unbind the event handler
});

This way, the event handler is attached only when needed and removed when it's no longer necessary, preventing unnecessary event handling and potential memory leaks.

At Online Learner, we're on a mission to ignite a passion for learning and empower individuals to reach their full potential. Founded by a team of dedicated educators and industry experts, our platform is designed to provide accessible and engaging educational resources for learners of all ages and backgrounds.

Disclaimer About Us