Excellent Typescript Test - 87+ MCQs: TypeScript test: Evaluate Your Programming Skills with TypeScript Questions and Answers

1. What is the purpose of TypeScript's 'null' and 'undefined' types?

To represent the absence of a value

To define a class

To create a loop

To print output

2. What is the purpose of the 'break' statement in TypeScript?

To continue to the next iteration

To exit a loop or switch statement

To skip a loop iteration

To declare a function

3. What is TypeScript's 'tuple' data type used for?

To define a class

To create a loop

To represent an array with a fixed number of elements of different data types

To print output

4. What is the purpose of TypeScript's 'readonly' modifier?

To define a class

To create a loop

To make a property or variable immutable

To print output

5. What is the TypeScript feature used to combine multiple types into a single type?

Type casting

Type assertion

Union type

Intersection type

6. In TypeScript, what is the 'any' type used for?

To define a class

To create a loop

To represent a variable with an unknown or dynamic type

To print output

7. What is the use of the 'declare' keyword in TypeScript?

To define a new variable

To declare the type of a variable without initializing it

To declare a dependency

To declare a new function

8. Which data type is used to represent a collection of values in TypeScript?

array

list

set

collection

9. What is TypeScript?

A markup language

A programming language

A database system

A text editor

10. In TypeScript, how do you declare a variable with a specific type?

let variableName: type = value;

var variableName = value;

variableName type = value;

const variableName = value;

11. What is the use of the 'this' parameter in TypeScript functions?

To refer to the current class instance

To explicitly specify the type of 'this' within a function

To declare a new variable

To refer to the global scope

12. What is the purpose of the 'extends' keyword in TypeScript?

To create a new class

To declare a variable

To extend the functionality of a class

To define a function

13. What is the TypeScript equivalent of JavaScript's 'for...in' loop?

for...in

for...of

forEach

while

14. What is the purpose of namespaces in TypeScript?

To bundle related interfaces and classes

To create a new module

To define a new scope for variables

To import external libraries

15. Which keyword is used to declare a constant variable in TypeScript?

let

var

const

readonly

16. In TypeScript, which of the following is the correct way to define an array of numbers?

let numbers: number[];

let numbers: array<number>;

let numbers: Array[number];

let numbers: [number];

17. Which TypeScript feature is used to create a new type that is composed of existing types?

Type casting

Type assertion

Union type

Intersection type

18. What is TypeScript's 'type alias' used for?

To define a class

To create a new object

To create a custom name for a data type

To print output

19. What is TypeScript's 'type inference'?

A feature that allows automatic conversion of data types

A feature that infers the type of a variable based on its value

A feature that enforces strict typing

A feature that defines custom data types

20. What is the purpose of TypeScript's 'import' statement?

To export a module

To import a module or module member

To create a new file

To define a class

21. What is TypeScript's equivalent of JavaScript's 'null'?

undefined

void

null

nil

22. Which of the following correctly describes the 'Partial' utility type in TypeScript?

Transforms all properties of a type to be optional

Transforms all properties of a type to be readonly

Creates a type with all properties of another type, excluding some

Extracts a subset of properties from a type

23. Which keyword is used to declare a variable in TypeScript with a specific type?

var

let

type

const

24. Which utility type constructs a type by picking the set of properties 'K' from 'T'?

Pick<T, K>

Omit<T, K>

Partial<T>

Exclude<T, U>

25. What is the purpose of TypeScript's 'typeof' operator?

To check the type of an expression

To declare a variable

To create an object

To define a function

26. How can you declare a variable that can either be a number or a null in TypeScript?

let variable: number | null;

let variable: number & null;

let variable: null[number];

let variable: number = null;

27. In TypeScript, what is the purpose of the 'namespace' keyword?

To define a class

To create a loop

To group related code into a named container

To print output

28. In TypeScript, how do you define an optional function parameter?

By using 'optional' keyword

By using 'required' keyword

By using a question mark '?'

By using a colon ':'

29. How do you define a class in TypeScript?

class MyClass {}

create class MyClass {}

new class MyClass {}

type MyClass {}

30. In TypeScript, what is the purpose of the 'try/catch' statement?

To define a class

To create a loop

To handle exceptions and errors

To print output

31. What is the correct way to annotate a function return type in TypeScript?

function example(): returnType

function example() -> returnType

returnType function example()

function example() returns returnType

32. What does the 'as' keyword do in TypeScript?

Type casting

Variable declaration

Function invocation

Type checking

33. Which TypeScript feature is used to apply metadata to classes, methods, or properties?

Access modifier

Type assertion

Decorator

Mixin

34. What does the 'is' keyword do in a TypeScript type predicate?

Checks if a type is assignable to another

Defines a custom type guard

Specifies an inheritance relationship

Creates a conditional type

35. What is TypeScript's 'export' keyword used for?

To import a module

To define a class

To export a module or module member

To declare a variable

36. What is the purpose of TypeScript's 'class' keyword?

To declare a new function

To create an instance of a class

To define a new data type

To define a blueprint for creating objects

37. Which TypeScript keyword is used to indicate that a function doesn't return any value?

none

null

undefined

void

38. How do you define a function in TypeScript?

function functionName() {}

const functionName = () => {}

def functionName() {}

method functionName() {}

39. Which is the correct way to define a class that implements an interface in TypeScript?

class ExampleClass implements ExampleInterface {}

class ExampleClass extends ExampleInterface {}

interface ExampleClass implements ExampleInterface {}

class ExampleClass: ExampleInterface {}

40. What is TypeScript's 'module' system used for?

To define a class

To create a loop

To organize and encapsulate code into reusable units

To print output

41. How do you declare a readonly array in TypeScript?

let readonlyArray: ReadonlyArray<number>

let readonlyArray: number[] readonly

readonly let readonlyArray: number[]

let readonlyArray: const number[]

42. In TypeScript, how do you define a function?

func myFunction() {}

function myFunction() {}

method myFunction() {}

def myFunction() {}

43. How do you define a tuple type in TypeScript?

[type1, type2]

{type1, type2}

(type1, type2)

type1 | type2

44. What is a discriminated union in TypeScript?

A union type that includes discriminant properties

A union type that excludes certain types

A special type of intersection type

A union type that is discriminated by the compiler

45. Which TypeScript feature is used to make a property or method in a class inaccessible from outside the class?

Access modifier

Decorator

Mixin

Type assertion

46. In TypeScript, how do you define a tuple?

(1, 2, 3)

[1, 2, 3]

{1, 2, 3}

<1, 2, 3>

47. How do you define an optional property in a TypeScript interface?

prop?: type

optional prop: type

prop: type?

prop: optional type

48. What TypeScript feature allows for specifying an exact set of string values for a type?

Enum

Literal Types

Union Types

Type Aliases

49. What is TypeScript primarily used for?

Developing mobile applications

Server-side scripting

Creating responsive web designs

Enhancing JavaScript with static typing

50. Which of the following is the correct way to define an interface for a function in TypeScript?

interface ExampleFunction { (param1: type1, param2: type2): returnType }

interface ExampleFunction { function(param1: type1, param2: type2): returnType }

function ExampleFunction(param1: type1, param2: type2): returnType;

type ExampleFunction = (param1: type1, param2: type2) => returnType;

TypeScript MCQ Test 1