Class property declarations in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a public property named name of type string.

Typescript

class Person {
  public [1]: string;
}

Drag options to blanks, or click blank then click option'

Aname

Bage

Cprivate

Dconstructor

Attempts:

3 left

💡 Hint

Common Mistakes

Using a keyword like 'private' as the property name.

Forgetting to specify the property name.

The property name is declared as a public string property inside the class.

2fill in blank

medium

Complete the code to declare a private property named age of type number.

Typescript

class Person {
  private [1]: number;
}

Drag options to blanks, or click blank then click option'

Aname

Bage

Cpublic

Dstring

Attempts:

3 left

💡 Hint

Common Mistakes

Using public instead of private.

Using a wrong type like string instead of number.

The property age is declared as a private number property inside the class.

3fill in blank

hard

Fix the error in the property declaration to make isActive a boolean property.

Typescript

class User {
  isActive: [1];
}

Drag options to blanks, or click blank then click option'

Anumber

Bstring

Cboolean

Dany

Attempts:

3 left

💡 Hint

Common Mistakes

Using string or number instead of boolean.

Omitting the type annotation.

The property isActive should be declared with type boolean to hold true/false values.

4fill in blank

hard

Fill both blanks to declare a readonly property id of type number.

Typescript

class Product {
  [1] [2]: number;
}

Drag options to blanks, or click blank then click option'

Areadonly

Bprivate

Cid

Dpublic

Attempts:

3 left

💡 Hint

Common Mistakes

Using private or public instead of readonly.

Swapping the order of property name and modifier.

The property id is declared as readonly so it cannot be changed after initialization, and its type is number.

5fill in blank

hard

Fill all three blanks to declare a protected property email of type string with an initial value.

Typescript

class Account {
  protected [1]: [2] = [3];
}

Drag options to blanks, or click blank then click option'

Aemail

Bstring

C'[e-mail]'

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using number type instead of string.

Forgetting to add the initial value.

Using incorrect quotes for the string value.

The property email is declared as protected so it is accessible in subclasses, has type string, and is initialized with the value '[e-mail]'.