What is the method for choosing an element by class name in TypeScript?

Question

What is the method for choosing an element by class name in TypeScript?

Currently, I'm working on creating a responsive menu bar that collapses on smaller screens. The challenge I'm facing is that I'm using TypeScript for this project. Is there any guidance on how to translate the following code into TypeScript?

function myFunction() {
document.getElementsByClassName("topnav")[0].classList.toggle("responsive");}

I attempted converting the code to TypeScript, but it seems to not be functioning correctly.

myFunction(): void {
(<HTMLScriptElement[]><any>document.getElementsByClassName("topnav"))[0].classList.toggle("responsive");
}

typescript

Answer 1

Answer №1

Typically, there is no need to make any changes as TypeScript is a superset of JavaScript, meaning regular JavaScript code can be treated as TypeScript.

However, you can take advantage of some TypeScript features if you choose to:

function myFunction(): boolean {
    let elements: NodeListOf<Element> = document.getElementsByClassName("topnav");
    let classes: DOMTokenList = elements[0].classList;
    return classes.toggle("responsive");
}

In reality, it's not necessary to complicate things like this, so you could simply keep your current code and just specify a return type for the function:

function myFunction(): void {
    document.getElementsByClassName("topnav")[0].classList.toggle("responsive");
}

Alternatively,

function myFunction(): boolean {
    return document.getElementsByClassName("topnav")[0].classList.toggle("responsive");
}

Answer 2

Typically, there is no need to make any changes as TypeScript is a superset of JavaScript, meaning regular JavaScript code can be treated as TypeScript.

However, you can take advantage of some TypeScript features if you choose to:

function myFunction(): boolean {
    let elements: NodeListOf<Element> = document.getElementsByClassName("topnav");
    let classes: DOMTokenList = elements[0].classList;
    return classes.toggle("responsive");
}

In reality, it's not necessary to complicate things like this, so you could simply keep your current code and just specify a return type for the function:

function myFunction(): void {
    document.getElementsByClassName("topnav")[0].classList.toggle("responsive");
}

Alternatively,

function myFunction(): boolean {
    return document.getElementsByClassName("topnav")[0].classList.toggle("responsive");
}

What is the method for choosing an element by class name in TypeScript?

Answer №1

Similar questions

What is the best practice for updating the state of a web component in a manner that can be tracked by history with vaadin-router?

Excluding a common attribute from a combined type of objects can lead to issues when accessing non-common attributes (TypeScript)

Ways to achieve outcomes from functions employing concatMap within rxjs?

The variable is accessed prior to being assigned with the use of the hasOwnProperty method

Error: Unable to iterate through posts due to a TypeError in next.js

Is there a way to inform TypeScript that an object can only return properties from values found within an array?

`Angular 6 and the expiration of Jwt tokens`

Customizing default attribute prop types of HTML input element in Typescript React

What is the proper way to specify the type for a <video> element reference in React when utilizing Typescript?

Enhancing IntelliSense to recognize exports specified in package.json

Synchronization problem encountered in an Angular app involving playwright

Error encountered with TypeScript compiler when using a React Stateless Function component

What is the code to continuously click on the "Next" button in playwright (typescript) until it is no longer visible?

Sorting array of arrays in TypeScript and Node.js involves defining the arrays and then applying a sorting algorithm

Expanding a class in Angular 2

Choose a single asset from the list of values stored in the Map

If every single item in an array satisfies a specific condition

Tips on utilizing index and eliminating React Warning: Ensure every child within a list has a distinct "key" prop

Utilize TypeScript to define the types based on the return values produced by an array of factory functions

Converting axios response containing an array of arrays into a TypeScript interface