How to check whether a string is a valid HTTP URL?

How to check whether a string is a valid HTTP URL?

The task of validating the validity of a URL can be simplified by leveraging the in-built URL constructor provided by JavaScript. To perform the validation, an attempt is made to create a new URL object by calling new URL(url). If the string representing the potential URL is well-formed, the operation will be successful, resulting in a valid URL object. However, if the string is not a valid URL, a TypeError is thrown. This method provides a straightforward approach to validation using exception handling.

Here’s an example to illustrate this approach:

// Function to check for valid HTTP URL
function isValidHTTPURL(string) {
    try {
        new URL(string);
        return true;
    } catch (error) {
        return false;
    }
}

// Sample test cases
const testCases = ["https://example.com", "http://localhost:8080", "ftp://example.com", "Invalid URL"];
testCases.forEach((testCase) => {
    console.log(`"${testCase}" is a valid HTTP URL: ${isValidHTTPURL(testCase)}`);
});

Output:

"https://example.com" is a valid HTTP URL: true
"http://localhost:8080" is a valid HTTP URL: true
"ftp://example.com" is a valid HTTP URL: false
"Invalid URL" is a valid HTTP URL: false

In this example, the isValidHTTPURL function takes a string as input and attempts to create a new URL object using JavaScript’s new URL constructor. If the string is a valid HTTP URL, the function returns true. Otherwise, it returns false, indicating that the string is not a valid HTTP URL.

This method provides a simple and effective way to check the validity of a URL string in JavaScript.