Why does ES 6 scold ":" in constructor?

Question

JavaScript

Dear comrades, help me deal with the problem, I've been sitting dumb for an hour and slowly starting to get psycho =).
Example :

import {Http} from 'angular2/http'

export class Test {
    constructor(http: Http) {
        this.http = http;
    }
}

Swears at ":" in the constructor and that's it.
"Module build failed: SyntaxError: /filepath/file.js: Unexpected token (14:10)"

Answer 1

this is TypeScript syntax and in native js it doesn't work