How can i avoid a function to be overridden in the Child Class in TypeScript ?

Question

According to the example given below , i don't want Class B or any other classes which extends A be able to override funcA.

Can this be done in TypeScript ? If yes then, How ?

export class A {
    protected funcA(){

    }
}

export class B extends A {
    //Not able to override funcA()

}

Answer 1

Update for TS 4.3 and above

Typescript 4.3 adds a new compiler option called noImplicitOverride in this PR. This makes it an error to mistakenly override class methods without the override keyword

class Base{
    method() {}
    method2 () {}
} 

class Derived extends Base {
    method() {} // err 
    override method2() {} // ok
} 

(playground does not support the option yet, but works in vs code)

Original answer pre 4.3

There is no way to prevent a public/protected member from beeing overriden. The compiler will trigger an error if you to this with private members only. A feature for this has been proposed but not implemented