herança.js

class User {
  constructor(firstName, lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
  }
  
  getFullName() {
    console.log(this.firstName + " " + this.lastName);  
  }
}

class Aluno extends User {
  constructor(firstName, lastName, turma) {
    super(firstName, lastName);
    this.turma = turma;
  }
}

const aluno = new Aluno("Jon", "Snow", "014")
console.log(aluno.getFullName()); // "Jon Snow"