How to get the background array in javascript

Javascript is a scripting language widely used in web front-end development. Together with HTML and CSS languages, it forms the three front-end foundations of web applications. One of its advantages is that it can access the background data array through concise code, thereby showing web page interaction effects, data display effects, etc.

In the following article, we will briefly introduce how to use javascript to get the background array, and provide you with some useful tips and practical examples.

Use JQuery Ajax technology to obtain background data

JQuery is a well-known javascript library. It encapsulates many convenient functions and methods internally. It is a very common practice to use the JQuery library to complete database operations. . In fact, JQuery Ajax technology is a very suitable method for obtaining background arrays. It can provide you with a clean and simple API interface, and it does not need to be polished with back-end languages ​​such as PHP and Java, making it very easy to use.

First, you need to use the JQuery AJAX method to make an HTTP request. This request will send a GET or POST request to the background, and pass the requested data (JSON, XML, etc.) to the front-end through the callback function. javascript code. Here is a simple example of an AJAX request:

$.ajax({
    url: "http://yourbackend.com/example.php",
    data: { name: "John", location: "Boston" }
}).done(function( data ) {
    console.log(data);
});

In the above code, you need to replace the URL link with your actual backend data source link. As you can see, the link 'http://yourbackend.com/example.php' points to a PHP file that stores backend array data. In the request, we sent a variable 'name' and a 'location' to the background file. These two data will be received by the background script and the corresponding JSON data will be returned based on this data.

After the request is completed, the AJAX callback function is called. In the callback function, you can process the obtained data, such as displaying the obtained array results on our page.

Based on this principle, you can easily write a javascript program that can obtain the background array. Before you can access the array, you need to implement a PHP or Java web server yourself, and point it to your web server in the AJAX request. After you successfully obtain the data from this back-end script, you need to use javascript code in the front-end page to parse the CSS so that the returned results are displayed on the user page.

On this basis, you can also extend AJAX with more functions according to business needs, such as paging to obtain background array data, filtering data, etc. In short, using AJAX technology, it is relatively simple to obtain background array data. You only need to spend a small amount of time writing a background script (PHP, JAVA, etc.), and then call this service in the front end.

Use Node.js and Express to get the array from the background

In addition to AJAX technology, if you use the same language on the front and back ends, you can also use some of the more popular Node. js technology to obtain the background array. For example, using the Express framework, which is a very popular Node.js web framework, it allows you to get backend array data from a website using very simple code.

In the following program example, we will use Express and Node.js to build a custom web app service and obtain the background array from the server:

const express = require('express');
const app = express();
const bodyParser = require('body-parser');
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: true
}));

var items = [
  'itemA',
  'itemB',
  'itemC'
];

app.get('/items', (req, res) => {
  res.send(items);
});

app.listen(3000, () => console.log('Example app listening on port 3000!'));

In the above example, we A simple Express API was built. In this API, we defined a /Items page. In this page, we use Node.js to pass the request from the server to this API, and then the items array defined in the backend server is finally returned in JSON format to the front end calling the API.

The main spirit of this example is to use Express to build the web framework and use Node.js to write the background logic of the custom API. This background logic needs to specify the data format and data processing logic in the background array based on business requirements (such as accessing third-party APIs, using databases, etc.).

In the front-end page, you need to use the HTTP request library provided by Node.js to call this back-end array. After successfully getting the data from the backend, you need to use JavaScript to parse the array and finally implement the data presentation function. In short, Node.js and Express, as web framework technologies, allow you to have a deeper understanding of how to obtain background array data and operate on this data.

Summary

In web development, obtaining data through javascript is one of the more common practices, and we have mentioned the two mainstream technologies (AJAX and Node.js). AJAX technology is a relatively more familiar technology because it is very common in front-end operations, while Node.js and Express are very popular back-end web framework technologies that allow you to customize API services and are very suitable for enterprise development. and other projects that can easily use web services.

So, you need to make technology choices based on specific business scenarios to achieve the best technology stack for obtaining background array data. At the same time, a deep understanding of javascript is also very helpful in making you an excellent web developer.

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