Strip HTML Tags from String
What is JavaScript?
JavaScript is a high-level, interpretable programming language that is mostly used in the implementation of attractive and sequential web pages. From day one of its discovery, the core technology of the World Wide Web is the kids of Netscape. The development of sites that are more interactive through JavaScript, for example, incorporating is one of the ways of responding to user input wantons such as mouse movements, form submissions, and clicks. It may dynamically update the DOM, reflecting user input or some other event that is added to a situation in which the website content can be changed during runtime. The two notable attributes of JavaScript are:
- It provides adaptability and client-side support (user's web browser) as well as server-side functionality (e.g., Node.js) in the hosting environment. It assists in creating web applications containing just the front-end and back-end code using a single language.
- JavaScript is not only a powerful tool that is simple to grasp due to its relative simplicity, but it also has a large number of complicated features for experienced programmers.
Introduction
When you wish to remove HTML tags from a string in JavaScript and sanitize user input to stop cross-site scripting ( XSS ) attacks, you frequently need to extract only the text content from an HTML page. All HTML tags are eliminated during this operation, leaving only the plain text content.
One popular way is to locate HTML elements and replace them with an empty string using a regular expression and the `replace` function. Any HTML tag needs to be matched by the regular expression { /<[^>]*>?/gm}, which replaces it with an empty string. The `m' argument enables the regex to match over multiple lines in the unlikely event that the HTML content spans several lines, and the `g` flag makes the replacement global, eliminating all instances of HTML tags.
Using Regular Expression
The first step in using regular expressions in JavaScript to remove HTML tags from a string is to locate and delete each instance of an HTML tag from the input string. Regular expressions are perfect for this sort of work since they are an effective tool for identifying patterns in strings.
The basic idea is to use a regular expression pattern that matches every HTML tag to replace every HTML element including its attributes with an empty string. This is a simple example of how to achieve this:
function stripHtmlTags(html) {
// Regular expression to match HTML tags
const regex = /<[^>]*>?/gm;
// Replace HTML tags with an empty string
return html.replace(regex, '');
}
In this example, the stripHtmlTags function accepts an HTML string as input and removes all HTML tags from the String using the replace method and the regular expression /[^>]*>?/gm. Any character sequence that begins with , is followed by zero or more characters that are not >, and ends with > is matchable by the regular expression [^>]*>? There is a global and multiline search using the gm flags.
Using DOM Parsing
Applying DOM Utilizing the browser's DOM (Document Object Model) parser to convert the HTML string into a DOM object and then extracting the text content from it is the process of parsing to remove HTML tags. Compared to regular expressions, this approach is more stable and dependable for handling HTML material since it can appropriately handle complicated HTML and is aware of the document structure.
How it operates?
- DOM Parser creation: To create a new DOM parser instance, use the DOMParser constructor.
- Compile the HTML text: Give the parseFromString function of the parser instance the HTML string. A DOM document object containing the parsed HTML is the result of the above operation.
- Extract the text's content: To obtain the text content devoid of HTML elements, access the text content property of the document's body element.
function stripHtmlTagsWithDom(html) {
// Create a new DOM parser instance
let parser = new DOMParser();
// Parse the HTML string into a DOM document
let doc = parser.parseFromString(html, 'text/html');
// Return the text content of the body element
return doc.body.textContent || "";
}
// Example usage
let htmlString = "< p>Hello, <b>world</b>!</p>";
let textContent = stripHtmlTagsWithDom(htmlString);
console.log(textContent); // Output: "Hello, world!"