Elm's primary selling point is "no runtime exceptions". The subheader on Elm's homepage even says this[1]:
Generate JavaScript with great performance and no runtime exceptions.
Here's a short example in Typescript:
import fetch from "node-fetch"
interface Post {
user_id: number,
id: number,
title: string,
body: string
}
const postUrl = 'https://jsonplaceholder.typicode.com/posts/1'
const show = function(post: Post) {
console.log(post.user_id)
console.log(post.id)
console.log(post.title)
console.log(post.body)
}
function getJSON(): Promise<Post> {
return fetch(postUrl).then(x => x.json())
}
getJSON().then(show)
Everything in programming is about tradeoffs. If you don't care about strong type correctness, use something like Typescript. If you do care, Elm is a great choice.
[1]: http://elm-lang.org/