How to perform a dns lookup from hostname to IP address using client-side JavaScript?

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In client-side JavaScript, you can perform a DNS lookup from hostname to IP address using the window.fetch() method and a third-party DNS lookup API that provides a JSON or JSONP response. Here’s an example of how to do it using the jsonp package:

// Import the jsonp package
import jsonp from 'jsonp';

// Set the hostname to lookup
const hostname = 'example.com';

// Make a DNS lookup request using the jsonp package
jsonp(`https://dns.google.com/resolve?name=${hostname}&type=A`, null, (error, data) => {
  if (error) {
    console.error(error);
    return;
  }
  
  // Extract the IP address from the response
  const ipAddress = data.Answer[0].data;
  console.log(`The IP address of ${hostname} is ${ipAddress}.`);
});

In the above example, we import the jsonp package, which provides a JSONP client for making cross-domain requests. We then set the hostname variable to the hostname we want to lookup. We make a DNS lookup request to Google’s public DNS server (dns.google.com) using the jsonp() method and pass the hostname and the record type (in this case, A) as parameters. We then extract the IP address from the response data and log it to the console.

Note that this approach requires the use of a third-party DNS lookup API, as client-side JavaScript does not have direct access to the underlying operating system’s DNS resolver. You may need to check the terms of service and usage limits of any API you use to ensure you are not violating any restrictions. Additionally, some DNS lookup APIs may not support all record types or may have limited availability or accuracy.

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