Category: JavaScript

Sometimes, we want to generate random string for div ID with JavaScript.

In this article, we’ll look at how to generate random string for div ID with JavaScript.

How to generate random string for div ID with JavaScript?

To generate random string for div ID with JavaScript, we can create a random base64 string.

To do this, we write

const id = btoa(Math.random()).substring(0, 12);

to call Math.random to create a random number between 0 and 1.

Then we call btoa on the returned number to convert it to a base64 string.

Next, we call substring with 0 and 12 to return a string with the first 12 characters of the base64 string.

Conclusion

To generate random string for div ID with JavaScript, we can create a random base64 string.

Sometimes, we want to detect if user is scrolling with JavaScript.

In this article, we’ll look at how to detect if user is scrolling with JavaScript.

How to detect if user is scrolling with JavaScript?

To detect if user is scrolling with JavaScript, we can listen to the window’s scroll event.

For instance, we write

let userHasScrolled = false;
window.onscroll = (e) => {
  userHasScrolled = true;
};

to set window.onscroll to a function that sets userHasScrolled to true when we scroll in the window.

Then if userHasScrolled is true, we know the user scrolled.

Conclusion

To detect if user is scrolling with JavaScript, we can listen to the window’s scroll event.

Sometimes, we want to print JavaScript exception stack trace.

In this article, we’ll look at how to print JavaScript exception stack trace.

How to print JavaScript exception stack trace?

To print JavaScript exception stack trace, we can use the stack property of an Error instance.

For instance, we write

console.log(new Error().stack);

to create a new Error instance and then get the stack trace from the stack property.

Then we use console.log to log the stack trace.

We put this in the line where we want to print the stack trace to the console.

Conclusion

To print JavaScript exception stack trace, we can use the stack property of an Error instance.

Sometimes, we want to sort or order keys in JavaScript objects.

In this article, we’ll look at how to sort or order keys in JavaScript objects.

How to sort or order keys in JavaScript objects?

To sort or order keys in JavaScript objects, we can use the Object.keys method and the array sort and reduce methods.

For instance, we write

const notSorted = { b: false, a: true };

const sorted = Object.keys(notSorted)
  .sort()
  .reduce(
    (acc, key) => ({
      ...acc,
      [key]: notSorted[key],
    }),
    {}
  );

console.log(sorted);

to call Object.keys with notSorted to get the keys of the notSorted object in an array.

Then we call sort to sort the keys.

Then we call reduce with the sorted keys array with a callback to get the keys and values and put them in a new object.

The new object with the sort keys is then returned by reduce.

Conclusion

To sort or order keys in JavaScript objects, we can use the Object.keys method and the array sort and reduce methods.