Category: JavaScript Answers

Sometimes, we want to fix firebase.firestore() is not a function when trying to initialize Cloud Firestore with JavaScript.

In this article, we’ll look at how to fix firebase.firestore() is not a function when trying to initialize Cloud Firestore with JavaScript.

How to fix firebase.firestore() is not a function when trying to initialize Cloud Firestore with JavaScript?

To fix firebase.firestore() is not a function when trying to initialize Cloud Firestore with JavaScript, we need to import the Firestore modules.

For instance, we write

import firebase from "firebase/app";
import "firebase/firestore";

to imoort firebase and firebase/firestore to import the required dependencies.

Conclusion

To fix firebase.firestore() is not a function when trying to initialize Cloud Firestore with JavaScript, we need to import the Firestore modules.

Sometimes, we want to check for keyCode values for numeric keypad with JavaScript.

In this article, we’ll look at how to check for keyCode values for numeric keypad with JavaScript.

How to check for keyCode values for numeric keypad with JavaScript?

To check for keyCode values for numeric keypad with JavaScript, we can check for the key code ranges for numeric keys.

For instance, we write

if (
  (e.keyCode >= 48 && e.keyCode <= 57) ||
  (e.keyCode >= 96 && e.keyCode <= 105)
) {
  // ...
}

to check for presses for the digit keys.

The digit keys on the top of the keyboard has key code range 48 to 57.

The digit keys on the numeric keypad has key code range 96 and 105.

Conclusion

To check for keyCode values for numeric keypad with JavaScript, we can check for the key code ranges for numeric keys.

Sometimes, we want to restart animation in CSS3 and JavaScript.

In this article, we’ll look at how to restart animation in CSS3 and JavaScript.

How to restart animation in CSS3 and JavaScript?

To restart animation in CSS3 and JavaScript, we use the Animation API.

For instance, we write

const effect = new KeyframeEffect(
  el,
  [{ transform: "translateY(0%)" }, { transform: "translateY(100%)" }],
  { duration: 3000, direction: "alternate", easing: "linear" }
);

const animation = new Animation(effect, document.timeline);

animation.play();

to create the effect object with the KeyframeEffect constructor.

We call it with the el element we want to animate, an array of effects, and some animation options.

Options includes the animation duration, direction, and easing.

Then we create the Animation object with effect and document.timeline.

document.timeline is the default timeline of the current document.

Then we call play to play the animation.

Conclusion

To restart animation in CSS3 and JavaScript, we use the Animation API.

Sometimes, we want to create date regex that matches DD/MM/YYYY format with JavaScript.

In this article, we’ll look at how to create date regex that matches DD/MM/YYYY format with JavaScript.

How to create date regex that matches DD/MM/YYYY format with JavaScript?

To create date regex that matches DD/MM/YYYY format with JavaScript, we can create a regex that matches the date pattern.

For instance, we write

/[0-9]{2}[/][0-9]{2}[/][0-9]{4}$/;

to match DD and MM with [0-9]{2}.

Then we match YYYY with [/][0-9]{4}.

We make sure YYYY is at the end of the string with $.

Conclusion

To create date regex that matches DD/MM/YYYY format with JavaScript, we can create a regex that matches the date pattern.

Sometimes, we want to limit the length of an array in JavaScript.

In this article, we’ll look at how to limit the length of an array in JavaScript.

How to limit the length of an array in JavaScript?

To limit the length of an array in JavaScript, we can set the length property to the max length of the array.

For instance, we write

arr.length = Math.min(arr.length, 5);

to set arr.length to the minimum number between arr.length and 5.

Then arr can’t have length more than 5.

Conclusion

To limit the length of an array in JavaScript, we can set the length property to the max length of the array.