Why Are Private Members Accessible in JavaScript When Using TypeScript?

Exploring Private Members in TypeScript: Understanding Accessibility Discrepancy

In TypeScript, private members are used to restrict access within the enclosing class. However, users may encounter situations where private members appear accessible in JavaScript code. To clarify this issue, let's delve into TypeScript's implementation of private members.

According to the TypeScript documentation, private members are enforced only within the compiler for type checking purposes. In pure JavaScript, private members are implemented as regular properties. This means that code outside the class can potentially access them.

In the provided example:

class Test {
  private member: any = "private member";
}
alert(new Test().member);

member is declared as private within the class Test, indicating that it should only be accessible within the class. However, the JavaScript code is able to access it using new Test().member.

To truly restrict access to a member, it cannot exist as a class member. Instead, it can be declared as a local variable within a function scope that creates the object. This approach prevents access using the this keyword, ensuring genuine privacy.

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