Typing using the colon syntax
This is the general way of typing the variables in TypeScript that can also be used to assert the HTMLElement as well in TypeScript.
Syntax:
const var_name: type = value;
Example: The below example will show you how the colons can be used to assert HTMLElement in TypeScript.
Javascript
const appDiv: HTMLElement = document.getElementById( 'app' ); appDiv.innerHTML = `<h1> ${ typeof appDiv} </h1>`; |
HTML
<!DOCTYPE html> < html > < head > < title >Page Title</ title > </ head > < body > < h2 >Welcome To GFG</ h2 > < div id = "app" ></ div > </ body > </ html > |
Output:
Object
How to Assert a Type of an HTMLElement in TypeScript ?
In this article, we are going to learn the different ways of asserting the type of an HTMLElement in TypeScript. The type assertion is used to type the simple variables to JavaScript objects by defining the HTML element name.
There are many ways of performing this task as listed below:
Table of Content
- Typing using the colon syntax
- Using <> to assert typecast
- Using item() method with asserting type
- Using the any type with asserting type