T

Klassen

TypeScript Syntax Guide

Objektorientierte Programmierung mit typisierten Klassen in TypeScript

Klassen

Objektorientierte Programmierung mit typisierten Klassen in TypeScript

TypeScript klassen (typescript)
        
          // Class with type annotations
class Person {
  // Property types
  name: string;
  private age: number;
  protected email: string;

  // Constructor
  constructor(name: string, age: number, email: string) {
    this.name = name;
    this.age = age;
    this.email = email;
  }

  // Method
  greet(): string {
    return `Hello, I'm ${this.name}`;
  }

  // Getter/Setter
  get isAdult(): boolean {
    return this.age >= 18;
  }

  set updateAge(newAge: number) {
    if (newAge >= 0) {
      this.age = newAge;
    }
  }

  // Static method
  static createAnonymous(): Person {
    return new Person("Anonymous", 0, "anonymous@example.com");
  }
}

// Inheritance
class Employee extends Person {
  jobTitle: string;
  salary: number;

  constructor(name: string, age: number, email: string, jobTitle: string, salary: number) {
    super(name, age, email);
    this.jobTitle = jobTitle;
    this.salary = salary;
  }

  work(): string {
    return `${this.name} is working as ${this.jobTitle}`;
  }

  // Method override
  greet(): string {
    return `${super.greet()} and I work as ${this.jobTitle}`;
  }
}

// Abstract classes
abstract class Shape {
  abstract getArea(): number;

  getDescription(): string {
    return `Area: ${this.getArea()}`;
  }
}

class Rectangle extends Shape {
  constructor(private width: number, private height: number) {
    super();
  }

  getArea(): number {
    return this.width * this.height;
  }
}

// Usage
const person = new Person("John", 25, "john@example.com");
const employee = new Employee("Jane", 30, "jane@example.com", "Developer", 75000);
const rect = new Rectangle(10, 20);

console.log(person.greet()); // Hello, I'm John
console.log(employee.greet()); // Hello, I'm Jane and I work as Developer
console.log(rect.getArea()); // 200
        
      

Explanation

TypeScript erweitert JavaScript-Klassen mit Features wie Zugriffsmodifikatoren (public, private, protected) und Interfaces für Klassenimplementierung, was robustes objektorientiertes Design fördert.

Common Use Cases

  • Erstellen komplexer Anwendungen mit klaren Objektstrukturen
  • Implementieren von Design-Patterns
  • Erstellen wiederverwendbarer Komponenten

Related TypeScript Syntax

Master Klassen in TypeScript

Understanding Klassen is fundamental to writing clean and efficient TypeScript code. This comprehensive guide provides you with practical examples and detailed explanations to help you master this important concept.

Whether you're a beginner learning the basics or an experienced developer looking to refresh your knowledge, our examples cover real-world scenarios and best practices for using Klassen effectively in your TypeScript projects.

Key Takeaways

  • Erstellen komplexer Anwendungen mit klaren Objektstrukturen
  • Implementieren von Design-Patterns
  • Erstellen wiederverwendbarer Komponenten