What is the order of event capture?

The event capture sequence starts from the outermost element and passes downward layer by layer until it reaches the target element. This process can be viewed as an "event flow", where events start from the outermost element, pass through the event bubbling stage, and finally reach the target element. This process can help developers obtain target elements and contextual information, customize event processing logic, effectively prevent event bubbling, and improve page response speed. In actual development, event capturing and event bubbling are often used together to achieve a more flexible event handling method.

The operating system for this tutorial: Windows 10 system, DELL G3 computer.

The order of event capture refers to the processing order in the process of events being transmitted from the outermost element to the target element. In the event capture phase, events are passed down from the outermost element until the target element is found. In this process, each layer of elements will trigger the corresponding event handler.

The event capture sequence usually starts from the outermost element and passes down layer by layer until it reaches the target element. This process can be viewed as an "event flow", where events start from the outermost element, pass through the event bubbling stage, and finally reach the target element.

Specifically, when an event occurs, the browser will first check whether the outermost element is bound to the corresponding event handler. If an event handler exists, the browser executes the handler and passes the event object to the next element. This process is passed down layer by layer until the target element is found. On each layer of elements, developers can bind corresponding event handlers to handle events.

It should be noted that event capturing and event bubbling are related to each other. Event bubbling refers to the process in which events start from the target element and are passed up to the outermost element layer by layer. It is the reverse process of event capture. During the event capture phase, developers can prevent further delivery of the event or add custom logic in the event handler.

In actual development, event capture and event bubbling are often used together to achieve a more flexible event handling method. Developers can choose to perform event processing in the event capture phase or the event bubbling phase as needed, as well as add custom logic and optimization strategies.

In short, the event capture sequence refers to the process in which the event is passed from the outermost element to the target element, and the corresponding event handler is executed in a layer-by-layer manner. This process can help developers obtain target elements and contextual information, customize event processing logic, effectively prevent event bubbling, and improve page response speed.

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