How to write events in jquery

jQuery is a popular JavaScript library that plays an important role in our web development. Among them, events are important interactive elements on the page and can be the key to achieving various interactive effects. So, in this article, we will discuss in depth how to write events in jQuery.

1. Binding events

In jQuery, you can use the .on() method to bind events. This method requires at least two parameters. The first parameter is the event type, such as click, mouseover, keydown, etc. The second parameter is the function to be executed, that is, the code to be executed when the event is triggered.

For example, the following code will bind click events to all elements with class "button":

$(".button").on('click', function(){
    //执行点击事件时要执行的代码
})

2. Bind multiple events

If you need to give an element To bind multiple events, the event types can be separated by spaces. For example, the following code will trigger events when clicking and double-clicking at the same time:

$("#btn").on('click dblclick', function(){
    //执行事件时要执行的代码
});

3. Multiple elements are bound to the same event

When multiple elements need to be bound to the same event, you can Select these elements with a selector and bind them to the same event. For example, the following code binds all elements with class "button" to the same click event:

$(".button").on('click', function(){
    //执行点击事件时要执行的代码
});

4. Dynamic element binding event

If you need to dynamically add elements on the page , and you need to bind events to these elements, you can use jQuery's event delegation. Event delegation refers to binding events to parent elements rather than directly to child elements. When a child element fires an event, the event is passed to the parent element. For example, the following code binds click events to the p tags on all existing or future .content elements:

$(".content").on('click', 'p', function(){
    //执行点击事件时要执行的代码
});

5. Unbinding events

Unbinding events can be used off() method. For example, the following code will unbind the click event of all elements:

$("*").off('click');

6. Prevent event bubbling

When an event is triggered on an element, the event will be raised Passed to the element's parent element, this is called event bubbling. If you need to prevent the event from bubbling, you can use the stopPropagation() method in the event handler. For example, the following code will cancel bubbling:

$(".button").on('click', function(e){
    e.stopPropagation();
});

7. Prevent event default behavior

The default behavior of some elements may interfere with other interactive effects on the web page. If you need to cancel the default behavior of an event, you can use the preventDefault() method in the event handler. For example, the following code will cancel the default jump behavior of the link:

$("a").on('click', function(e){
    e.preventDefault();
});

Summary:

The above is the discussion of events in jQuery in this article. Through learning, we can clearly understand how to bind events, bind multiple events, bind multiple elements to the same event, and so on. At the same time, we also learned techniques such as dynamic element binding events, unbinding events, preventing event bubbling, and preventing event default behaviors. By mastering these technologies, we can more easily achieve various interactive effects on the page and make the web page more lively.

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