/** * Task 3: Analyze the function below and fix any errors. Explain the role of the `never` type in TypeScript. */ function throwError(): never { throw new Error('An error occurred'); } /** * Task 4: Transform the given type `MaybeProps` to make all of its properties required. */ type MaybeProps = { a?: number; b?: string; }; /** * Task 5: Create a generic type `Container` that contains a single property `value`. * The type of `value` should be constrained to either `string` or `number`. */ type Container<T> = { value: T; };

The throwError function is correct and contains no errors. It returns a never type, which means that the function will never complete normally (for example, it always throws an exception or runs infinitely).

The role of the never type in TypeScript

The never type is used to denote values that never occur. This is useful for functions that:

• Always throw an exception
• Never return control (for example, infinite loops)

This helps the compiler understand that code after such a function call will not continue.

---

Task 4: Make all properties of MaybeProps mandatory

You can use the built-in utility type Required<T>:

 type MaybeProps = {
 a?: number;
 b?: string;
 };

 type RequiredProps = Required<MaybeProps>;
 // Now RequiredProps: { a: number; b: string; }

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Task 5: Create a generic Container type constrained to string or number

To restrict the type T, you can use extends:

type Container<T extends string | number> = {
 value: T;
};

// Example usage:
const stringContainer: Container<string> = { value: "hello" };
const numberContainer: Container<number> = { value: 42 };

// Error:
// const boolContainer: Container<boolean> = { value: true }; // boolean is not allowed