CodeBlanks Logo Icon CodeBlanks
Login Register

Question pool

Write the question pool as a module.

Question pool module

The question pool is a data source containing all questions of the quiz. It is written as a module and exported with export. This way other files can use the pool via import. Keeping questions separate separates data from logic and makes maintenance easier.

// questions.ts
export const questions: Question[] = [
  { text: "a?", options: ["x", "y"], correctIndex: 0 }
];

Type-safe question array

The question pool is a Soru[] array. Thanks to the type annotation, the compiler errors if you add a misshapen question. This is the safest way to maintain data consistency. For example, a question missing dogruIndex is caught at compile time.

const questions: Question[] = [
  { text: "2+2?", options: ["3", "4"], correctIndex: 1 }
];

Practice Create a question pool

Define a Soru interface: metin: string, dogruIndex: number. Create an array named havuz of type Soru[] and add two questions: first with text "soru1" and dogruIndex: 0, second with text "soru2" and dogruIndex: 1. Print havuz.length with console.log.

Starter code

index.ts
// Soru interface tanımla
// havuz adında Soru[] dizisi oluştur
// iki soru ekle
// havuz.length yazdır

Sample solution

index.ts
interface Soru {
  metin: string;
  dogruIndex: number;
}
const havuz: Soru[] = [
  { metin: "soru1", dogruIndex: 0 },
  { metin: "soru2", dogruIndex: 1 }
];
console.log(havuz.length);

Expected output

2

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What is done to make the question pool usable from other files?

  • Declared with const
  • Printed with console.log
  • Placed inside an interface
  • Exported with export Correct answer

Explanation: The export keyword is used to export a value from a module; other files access it via import.

2 Array type annotation

Question 
const sorular: ____[] = [
  { metin: "a?", siklar: ["x"], dogruIndex: 0 }
];
Answer 
const sorular: Soru[] = [
  { metin: "a?", siklar: ["x"], dogruIndex: 0 }
];

Explanation: An array of Soru objects is annotated as Soru[]; this provides compile-time checking.

3 Question pool concepts

Term Meaning
export Export
Soru[] Question array type
modül Data-logic separation
import Import

All lessons in Intermediate

1 Classes

  1. Class basics
  2. Constructor and fields
  3. Methods
  4. Static members
  5. Summary - Classes

2 Access modifiers

  1. public
  2. private
  3. protected
  4. Parameter properties
  5. Summary - Access modifiers

3 Readonly properties

  1. readonly fields
  2. Readonly parameter
  3. Readonly vs const
  4. Summary - Readonly

4 Generics

  1. What is a generic?
  2. Generic functions
  3. Generic classes
  4. Multiple type parameters
  5. Summary - Generics

5 Generic constraints

  1. extends constraint
  2. keyof constraint
  3. Default type parameter
  4. Summary - Generic constraints

6 Utility types

  1. Partial
  2. Required and Pick
  3. Omit and Record
  4. Summary - Utility types

7 keyof and typeof

  1. keyof operator
  2. typeof operator
  3. Indexing with keyof
  4. Summary - keyof and typeof

8 Mapped types

  1. What is a mapped type?
  2. Readonly mapped type
  3. Optional mapped type
  4. Summary - Mapped types

9 Conditional types

  1. What is a conditional type?
  2. Distributive conditional
  3. Logic with conditional
  4. Summary - Conditional types

10 infer

  1. infer keyword
  2. Extracting from Promise
  3. Array element type
  4. Summary - infer

11 Decorators

  1. What is a decorator?
  2. Method decorator
  3. Property decorator
  4. Decorator factories
  5. Summary - Decorators

12 Modules

  1. export and import
  2. Default export
  3. Re-export
  4. Type-only import
  5. Summary - Modules

13 Namespaces

  1. What is a namespace?
  2. Nested namespace
  3. Namespace vs module
  4. Summary - Namespaces

14 Declaration files

  1. What is .d.ts?
  2. Ambient module
  3. Triple-slash directive
  4. Summary - Declaration files

15 Advanced classes

  1. abstract class
  2. implements
  3. Get and set
  4. Summary - Advanced classes

16 Type assertion

  1. as keyword
  2. angle bracket syntax
  3. Type assertion vs casting
  4. Casting from unknown
  5. Summary - Type assertion

17 Project: Library package

  1. Package design
  2. Exporting types
  3. Generic helpers
  4. Declaration file
  5. Integration

18 Project: Quiz app

  1. Question model
  2. Question pool
  3. Answer check
  4. Score calculation
  5. Integration

19 Project: Weather app

  1. Weather model
  2. API response type
  3. Data transform
  4. Display
  5. Integration

20 Intermediate final

  1. Challenge 1: Classes
  2. Challenge 2: Generics
  3. Challenge 3: Type systems
  4. Challenge 4: Mini app