What content is important in jquery

As a JavaScript library widely used in web development, jQuery has become one of the basic necessary skills for front-end developers. It simplifies the complexity of JavaScript and provides us with powerful DOM operations, event handling, animation effects, AJAX requests and other functions. So, what content in jQuery must developers master? This article will discuss the following aspects:

1. Selector

In jQuery, selector is one of the most basic and commonly used functions. jQuery provides a series of selectors, including basic selectors, hierarchical selectors, filter selectors, form element selectors, etc. Mastering these selectors can allow us to select DOM elements more quickly and accurately. For example:

$('#id') // ID 选择器
$('.class') // 类选择器
$('ul li') // 层次选择器
$('p:first') // 过滤选择器
$(':checkbox') // 表单元素选择器

2. DOM operation

How to use jQuery to operate DOM elements? This is one of the most basic and important features of jQuery. jQuery can use concise and clear syntax to implement operations such as inserting, deleting, and modifying DOM elements. For example:

$('p').html('新的内容') // 修改元素的 html 内容
$('ul').append('<li>新的列表项</li>') // 在 ul 中插入一个新的列表项
$('img').attr('src', 'new.jpg') // 修改图片的 src 属性
$('.box').remove() // 删除类名为 box 的元素

3. Event processing

In jQuery, we can use the on() method to add event listeners to elements, and we can also use the off() method to delete event listeners. This Greatly simplifies event handling operations. For example:

$('#btn').on('click', function () {
  // 点击事件处理程序
})

$('#btn').off('click', handler) // 删除点击事件监听器

4. Animation effects

jQuery provides a variety of animation effects, including hiding, displaying, sliding, fading in and out, etc. We can make the page elements move and increase the interactivity of the page by calling the corresponding methods. For example:

$('.box').hide(500) // 隐藏类名为 box 的元素，用500毫秒的时间来完成动画效果
$('.box').show(500) // 显示类名为 box 的元素，用500毫秒的时间来完成动画效果
$('.box').slideUp() // 向上滑动隐藏类名为 box 的元素
$('.box').fadeIn() // 淡入类名为 box 的元素

5. AJAX request

Using jQuery's AJAX function, we can load data asynchronously, update page content, and improve user experience. For example:

$.get('http://example.com/data', function (data) {
  // 成功获取数据后的回调函数
})

$.post('http://example.com/account', {name: 'John', password: '123456'}, function (data) {
  // 成功提交数据后的回调函数
})

Summary

The above is only part of jQuery, but for beginners, mastering these basic functions will make them handy in daily development. The power of jQuery lies in its simplicity and ease of use, which allows us to complete development tasks faster. Of course, in actual projects, we still need to continue to learn the advanced usage of jQuery, common problems, performance optimization, etc., and constantly improve our skills.

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