What is a capture event?

#In programming, capturing events refers to the process of monitoring and processing events. Events can be user interactions (such as clicks, mouse movements, etc.), system responses (such as timer triggering, network request completion, etc.), etc. When an event occurs, by capturing the event, the program can respond accordingly to these events.

In web development, capturing events usually involves the following steps:

1. Registering an event listener: Developers do this by calling a specific API (such as addEventListener ) to register a listener and tell the program to execute the corresponding code when a specific event occurs.

2. Define event handling function: Developers define a function to respond to the occurrence of a specific event, such as performing certain actions when a user clicks a button.

3. Event capturing and bubbling: In the DOM event model, event capturing refers to propagation from outside to in, while event bubbling refers to propagation from inside to outside. In the capture phase, the event is first delivered to the outermost element and then propagates inwards step by step; in the bubbling phase, the event starts from the innermost element and then propagates outward step by step.

4. Handling events: When a registered event occurs, the corresponding event processing function will be called to execute predefined logic.

In short, capturing events refers to the process of monitoring and processing events in programming. It is one of the important mechanisms to achieve interactive and dynamic functions, especially in web development. key role.