What are the differences between Event.target and Event.currentTarget in JavaScript?
Antek N
In JavaScript, bothevent.target andevent.currentTarget are properties used to access elements involved in an event. However, they have different behaviors and represent different elements. Here's a detailed explanation of their differences:
1.event.target:
- Refers to the actual target element that triggered the event.
- Represents the lowest-level element where the event originated.
- Can be any descendant element within the target element.
- Remains the same throughout the event propagation unless explicitly modified.
- Useful when you need to determine the specific element that triggered the event, especially in cases where events can be nested or bubbling up through multiple elements.
2.event.currentTarget:
- Refers to the element to which the event handler is attached.
- Represents the element that currently handles the event.
- Can be the same asevent.target or an ancestor element.
- Can be dynamically changed during event propagation.
- Useful when you need to handle events on multiple elements using a single event listener and want to reference the element that is currently handling the event.
3. Event Propagation:
- Events in JavaScript propagate through the DOM hierarchy, from the target element up to the document root.
- Event propagation occurs in two phases: capturing phase and bubbling phase.
- During the capturing phase, the event moves from the document root to the target element.
- During the bubbling phase, the event moves from the target element up to the document root.
4. Event Delegation:
- Event delegation is a technique where a common parent element handles events for multiple child elements.
- By attaching a single event listener to a parent element, you can handle events on multiple child elements efficiently.
- In event delegation scenarios,event.target refers to the actual child element that triggered the event, whileevent.currentTarget refers to the parent element to which the event listener is attached.
5. Usage Scenarios:
-event.target is often used when you need to perform specific actions based on the element that directly triggered the event, such as identifying a clicked button or validating form inputs.
-event.currentTarget is commonly used when you have a single event handler for multiple elements and need to perform actions based on the currently active element or manipulate elements in relation to the handler.
Understanding the differences betweenevent.target andevent.currentTarget is crucial in event handling, especially when dealing with event propagation and delegation. Choosing the appropriate property depends on the specific use case and the desired behavior when accessing elements involved in an event.