Typescript Ts2339 Property Doesn't Exist On Type - Class Decleration

I am using exact example outlined in Typescript https://www.typescriptlang.org/docs/handbook/typescript-in-5-minutes.html#classes This is exact copy I am running in app.ts class S

Solution 1:

You are declaring some public properties of your class directly in the consctructor so you should use "this" keyword

classStudent{
    fullName: string;
    constructor(public firstName, public middleInitial, public lastName) {
        this.fullName = this.firstName + " " + this.middleInitial + " " + this.lastName;
    }
}

Edit : working fiddle

Solution 2:

This seems to work fine?

varStudent = (function() {
  functionStudent(firstName, middleInitial, lastName) {
    this.firstName = firstName;
    this.middleInitial = middleInitial;
    this.lastName = lastName;
    this.fullName = firstName + " " + middleInitial + " " + lastName;
  }
  returnStudent;
}());

functiongreeter(person) {
  return"Hello, " + person.firstName + " " + person.lastName;
}
var user = newStudent("Jane", "M.", "User");
document.body.innerHTML = greeter(user);

<!-- TYPESCRIPT
var Student = (function () {
    function Student(firstName, middleInitial, lastName) {
        this.firstName = firstName;
        this.middleInitial = middleInitial;
        this.lastName = lastName;
        this.fullName = firstName + " " + middleInitial + " " + lastName;
    }
    return Student;
}());
function greeter(person) {
    return "Hello, " + person.firstName + " " + person.lastName;
}
var user = new Student("Jane", "M.", "User");
document.body.innerHTML = greeter(user);
-->