Category: JavaScript

Sometimes, we want to perform a DNS lookup from hostname to IP address using client-side JavaScript.

In this article, we’ll look at how to perform a DNS lookup from hostname to IP address using client-side JavaScript.

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

To perform a DNS lookup from hostname to IP address using client-side JavaScript, we can use a 3rd party API.

For instance, we write

const response = await fetch("https://dns.google/resolve?name=example.com");
const json = await response.json();
console.log(json);

to call fetch in an async function to make a get request to https://dns.google/resolve with the name query parameter set to the hostname we want to resolve.

Then we get the IP address from the JSON response we get from response.json.

Conclusion

To perform a DNS lookup from hostname to IP address using client-side JavaScript, we can use a 3rd party API.

Sometimes, we want to check if iframe is loaded or it has a content with JavaScript.

In this article, we’ll look at how to check if iframe is loaded or it has a content with JavaScript.

How to check if iframe is loaded or it has a content with JavaScript?

To check if iframe is loaded or it has a content with JavaScript, we can set the iframe’s onload property to a function that runs when the iframe is loaded.

For instance, we write

document.querySelector("iframe").onload = () => {
  console.log("iframe loaded");
};

to select the iframe with querySelector.

Then we set its onload property to a function that runs when the iframe’s content is loaded.

Conclusion

To check if iframe is loaded or it has a content with JavaScript, we can set the iframe’s onload property to a function that runs when the iframe is loaded.

Sometimes, we want to find the size of a file in Node.js.

In this article, we’ll look at how to find the size of a file in Node.js.

How to find the size of a file in Node.js?

To find the size of a file in Node.js, we can use the fs.statSync method.

For instance, we write

const fs = require("fs");
const stats = fs.statSync("myfile.txt");
const fileSizeInBytes = stats.size;
const fileSizeInMegabytes = fileSizeInBytes / (1024 * 1024);

to call the fs.statSync method with the path of the file we want to get the size for.

Then we get the size in bytes with stats.size.

Next, we convert the number of bytes to megabytes by dividing it by 1024 * 1024.

Conclusion

To find the size of a file in Node.js, we can use the fs.statSync method.

Sometimes, we want to make Chrome Extension run every page load with JavaScript.

In this article, we’ll look at how to make Chrome Extension run every page load with JavaScript.

How to make Chrome Extension run every page load with JavaScript?

To make Chrome Extension run every page load with JavaScript, we call chrome.tabs.onUpdated.addListener with a callback to runs on every page load.

For instance, we write

chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  if (changeInfo.status === "complete") {
    // ...
  }
});

to call chrome.tabs.onUpdated.addListener with a callback that runs on every page load.

If changeInfo.status is 'complete', then the page is loaded and we can do whatever we want after the page is loaded.

Conclusion

To make Chrome Extension run every page load with JavaScript, we call chrome.tabs.onUpdated.addListener with a callback to runs on every page load.

Sometimes, we want to convert a HTMLElement to a string with JavaScript.

In this article, we’ll look at how to convert a HTMLElement to a string with JavaScript.

How to convert a HTMLElement to a string with JavaScript?

To convert a HTMLElement to a string with JavaScript, we can use the outerHTML property.

For instance, we write

const element = document.getElementById("new-element-1");
const elementHtml = element.outerHTML;

to get the element with getElementById.

Then we get the HTML code of the element with the outerHTML property.

Conclusion

To convert a HTMLElement to a string with JavaScript, we can use the outerHTML property.