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The URL of JavaScript does not have http
As one of the basic technologies of modern web development, JavaScript is commonly used to create dynamic web pages, respond to user input, and build web applications. In the process of developing web applications, the concepts of HTTP protocol and URL are involved. However, some web developers may be confused as to why JavaScript URLs do not have the HTTP protocol. This article will explain the cause of this problem.
First, let’s review the role of the HTTP protocol and URL. The HTTP protocol is a standard protocol for transferring files (such as HTML, CSS, JavaScript, etc.). It provides a reliable way to exchange information between web browsers and servers. The URL is a standard format used to locate Web resources. It contains the location and access method of the Web resource.
When browsing a web page, when a user accesses a URL address, the web browser will send an HTTP request to obtain the resource specified by the URL. If the resource exists, the server will return the resource in the form of an HTTP response, and the web browser will parse the resource and present it to the user.
Now the question comes: why does JavaScript’s link address (i.e. URL) not have HTTP?
The link address (URL) in JavaScript is a standard format used to point to Web resources. As we mentioned earlier, the URL contains the location and access method of the resource, and JavaScript code usually does not need to obtain and access resources through the HTTP protocol. Instead, they are usually loaded or embedded resources within the same web page.
For example, suppose you are developing a simple web page and using a JavaScript file in it. If you want to embed JavaScript code in a web page, you can use the following code to embed JavaScript code in the page:
<!DOCTYPE html> <html> <head> <title>My Web Page</title> </head> <body> <h1>Welcome to my web page!</h1> <script src="script.js"></script> </body> </html>
In this code, the 3f1c4e4b6b16bbbd69b2ee476dc4f83a
tag is used Load embedded JavaScript code. The referenced resource is the JavaScript file with the path "script.js"
. This path is relative to the location of the HTML file.
Please note that this URL does not contain the HTTP protocol. In fact, if you try to send an HTTP request to this URL, you will get a 404 error because this URL is not a valid HTTP resource.
However, this does not mean that JavaScript cannot obtain and send data through the HTTP protocol. In fact, we usually use JavaScript's XMLHttpRequest object to send HTTP requests. If we need to get data from the server side, we can use the following code:
var xhr = new XMLHttpRequest(); xhr.open("GET", "http://www.example.com/data", true); xhr.send();
In this example, we use the XMLHttpRequest object to send a GET request and it will be sent to http://www.example. com/data
. This URL contains HTTP protocol because we need to get data from the server through HTTP protocol.
To summarize, JavaScript’s URL address does not have HTTP protocol because JavaScript usually does not need to obtain and access Web resources through HTTP protocol. However, we can still use JavaScript's XMLHttpRequest object to send HTTP requests and get data to achieve higher-level web application functionality.
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