How to use item() method with asserting type In HTML
In this approach, we will select the typecasting element using the tagname and the item() method and then type it using as typingProperty.
Syntax:
const var_name = document.getElementsByTagName('tag_name').item(0) as assertionType
Example: The below example will show the use of the item() method to assert type.
Javascript
const appDiv = document.getElementsByTagName( 'div' ). item(0) as HTMLDivElement; 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