TypeScript Employee Hierarchy - Abstract Classes and Inheritance

TypeScript Classes and OOP : Exercise-15 with Solution

Write a TypeScript program that defines an abstract class Employee with properties such as name, employeeID, and an abstract method calculateSalary(). Create derived classes (e.g., FullTimeEmployee, PartTimeEmployee) that extend Employee and provide salary calculation logic based on employment type.

Sample Solution:

TypeScript Code:

// Abstract class Employee
abstract class Employee {
  constructor(public name: string, public employeeId: number) {}

  // Abstract method for calculating salary
  abstract calculateSalary(): number;
}

// Derived class FullTimeEmployee
class FullTimeEmployee extends Employee {
  constructor(name: string, employeeId: number, private monthlySalary: number) {
    super(name, employeeId);
  }

  // Implement the calculateSalary method for FullTimeEmployee
  calculateSalary(): number {
    return this.monthlySalary;
  }
}

// Derived class PartTimeEmployee
class PartTimeEmployee extends Employee {
  constructor(name: string, employeeId: number, private hourlyRate: number, private hoursWorked: number) {
    super(name, employeeId);
  }

  // Implement the calculateSalary method for PartTimeEmployee
  calculateSalary(): number {
    return this.hourlyRate * this.hoursWorked;
  }
}

// Create instances of FullTimeEmployee and PartTimeEmployee
const fullTimeEmployee = new FullTimeEmployee("Veerle Brock", 105, 6000);
const partTimeEmployee = new PartTimeEmployee("Alaya Neha", 104, 15, 40);

// Calculate and print salaries
console.log(`Full-Time Employee ${fullTimeEmployee.name}'s Salary: $${fullTimeEmployee.calculateSalary()}`);
console.log(`Part-Time Employee ${partTimeEmployee.name}'s Salary: $${partTimeEmployee.calculateSalary()}`);

Explanations:

In the exercise above -

• First, define an abstract class "Employee" with properties 'name' and 'employeeID', and an abstract method "calculateSalary()".
• Create two derived classes, "FullTimeEmployee" and "PartTimeEmployee", that extend "Employee". Each derived class provides its own implementation of the "calculateSalary()" method based on the employment type.
• Create instances of FullTimeEmployee and PartTimeEmployee, passing in relevant details like name, employeeID, and salary or hourly rate.
• Finally, calculate and print salaries for both types of employee.

Output:

"Full-Time Employee Veerle Brock's Salary: $6000"
"Part-Time Employee Alaya Neha's Salary: $600"

TypeScript Editor:

See the Pen TypeScript by w3resource (@w3resource) on CodePen.

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