Factory & Constructor Functions

What's the issue with this factory function implementation?

const createPerson = (name, age) => {
  const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1);
  return {
    name: capitalize(name),
    age,
    greet() {
      console.log(`Hello, I'm ${this.name}`);
    }
  };
};

It uses arrow functions which is bad practice
The capitalize function is recreated for each person
The capitalize helper function is recreated every time createPerson is called, which is inefficient. It should be defined outside the factory function since it doesn't depend on any instance-specific data. This would improve memory usage as all instances would share the same helper function: const capitalize = str => str.charAt(0).toUpperCase() + str.slice(1); const createPerson = (name, age) => ({ ... });
The greet method should use an arrow function
There is no input validation

Next Question (11/20)