Lære Getters and Setters | Classes Fundamentals


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class BankAccount {
  private _balance: number;

  constructor(initialBalance: number) {
    this._balance = initialBalance;
  }

  get balance(): number {
    return this._balance;
  }

  set balance(amount: number) {
    if (amount < 0) {
      throw new Error("Balance cannot be negative");
    }
    this._balance = amount;
  }
}

const account = new BankAccount(1000);
console.log(account.balance); // 1000
account.balance = 1500;
console.log(account.balance); // 1500
// account.balance = -500; // This will throw an error

Getters and setters in TypeScript classes let you control how properties are accessed and modified. Instead of exposing a property directly, you can use a getter to retrieve its value and a setter to update it. This approach lets you add logic, such as validation or transformation, whenever a property is read or written. By using getters and setters, you can prevent invalid states, enforce rules, or trigger side effects, all while keeping the property itself private and protected from direct changes. This encapsulation is a key part of object-oriented programming, helping you maintain clean, predictable, and robust code as your applications grow.

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class BankAccount {
  private _balance: number;

  constructor(initialBalance: number) {
    this._balance = initialBalance;
  }

  get balance(): number {
    return this._balance;
  }

  set balance(amount: number) {
    if (amount < 0) {
      throw new Error("Balance cannot be negative");
    }
    this._balance = amount;
  }
}

const account = new BankAccount(1000);
console.log(account.balance); // 1000
account.balance = 1500;
console.log(account.balance); // 1500
// account.balance = -500; // This will throw an error

Var alt klart?

Tak for dine kommentarer!

Sektion 1. Kapitel 4