How to implement a list in javascript

JavaScript is a widely used scripting language that can be used to interact with web pages and implement various functions in web pages. Among them, implementation list is one of the common applications of JavaScript. This article will explore how to use JavaScript to implement lists, and introduce some common list types and corresponding implementation methods.

Types of lists

In practical applications, our common list types include ordered lists (ordered lists, referred to as ol), unordered lists (unordered lists, referred to as ul) and definition lists (definition list, referred to as dl) three types.

• Ordered list: Each list item of an ordered list is arranged in numerical or alphabetical order. In HTML, ordered lists are represented by the <ol></ol> tag.
• Unordered list: Unlike an ordered list, the list items in an unordered list do not have a relative position arrangement relationship. In HTML, an unordered list is represented by the <ul></ul> tag.
• Definition list: Each list item in the definition list has a corresponding description, which is used to describe the detailed content of the list item. In HTML, a definition list is represented by the <dl></dl> tag.

Implementation of list

1. Implementation of ordered list

We can create an ordered list through JavaScript and add several list items to it. The code is as follows:

//创建有序列表
var ol = document.createElement('ol');
//创建列表项
var li1 = document.createElement('li');
li1.innerHTML = '列表项1';
var li2 = document.createElement('li');
li2.innerHTML = '列表项2';
var li3 = document.createElement('li');
li3.innerHTML = '列表项3';
//将列表项添加到有序列表中
ol.appendChild(li1);
ol.appendChild(li2);
ol.appendChild(li3);
//将有序列表添加到网页中
document.body.appendChild(ol);

In the above code, first use the createElement() method to create a new ordered list object, and use the appendChild() method to add it to it Three list items are added. Finally, use the appendChild() method to add this ordered list to the web page. After executing the code, we can see a list of three ordered list items appear on the web page.

2. Implementation of unordered list

The implementation of unordered list is similar to that of ordered list, just use <ul></ul> instead of &lt ;ol>, as shown below:

//创建无序列表
var ul = document.createElement('ul');
//创建列表项
var li1 = document.createElement('li');
li1.innerHTML = '列表项1';
var li2 = document.createElement('li');
li2.innerHTML = '列表项2';
var li3 = document.createElement('li');
li3.innerHTML = '列表项3';
//将列表项添加到无序列表中
ul.appendChild(li1);
ul.appendChild(li2);
ul.appendChild(li3);
//将无序列表添加到网页中
document.body.appendChild(ul);

In the above code, we create a new unordered list object, add three list items to it, and then add it to the web page . After executing the code, we can see a list of three unordered list items appear on the web page.

3. Implementation of definition list

The implementation of definition list is different from ordered list and unordered list. In a definition list, each list item contains a term and a description. To do this, we need to create the <dt></dt> and <dd></dd> tags to represent the term and description respectively. The code is implemented as follows:

//创建定义列表
var dl = document.createElement('dl');
//创建术语和描述
var dt1 = document.createElement('dt');
dt1.innerHTML = '术语1';
var dd1 = document.createElement('dd');
dd1.innerHTML = '描述1';
var dt2 = document.createElement('dt');
dt2.innerHTML = '术语2';
var dd2 = document.createElement('dd');
dd2.innerHTML = '描述2';
var dt3 = document.createElement('dt');
dt3.innerHTML = '术语3';
var dd3 = document.createElement('dd');
dd3.innerHTML = '描述3';
//将术语和描述添加到定义列表中
dl.appendChild(dt1);
dl.appendChild(dd1);
dl.appendChild(dt2);
dl.appendChild(dd2);
dl.appendChild(dt3);
dl.appendChild(dd3);
//将定义列表添加到网页中
document.body.appendChild(dl);

In the above code, we create a new definition list object and add three terms and their corresponding descriptions to it. Finally, add it to the web page. After executing the code, we can see a list of definitions containing three terms and a description appear on the web page.

Conclusion

JavaScript is a powerful and flexible scripting language that can implement many web page functions through code. Through the introduction of this article, we can see that by using JavaScript, we can easily create and manage many types of lists, thereby adding more interactivity and functionality to web pages.

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