Static members with types in Typescript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a static property named count of type number.

Typescript

class Counter {
  static [1]: number = 0;
}

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Avalue

Bcount

Ctotal

Dnumber

Attempts:

3 left

💡 Hint

Common Mistakes

Using instance property syntax instead of static

Choosing wrong property name

The static property is named count and typed as number.

2fill in blank

medium

Complete the code to declare a static method named getCount that returns a number.

Typescript

class Counter {
  static count: number = 0;
  static [1](): number {
    return Counter.count;
  }
}

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AsetCount

Bcount

CcountValue

DgetCount

Attempts:

3 left

💡 Hint

Common Mistakes

Using instance method syntax

Wrong method name

The static method to return the count is named getCount.

3fill in blank

hard

Fix the error in the static method declaration to correctly access the static property count.

Typescript

class Counter {
  static count: number = 0;
  static getCount(): number {
    return [1].count;
  }
}

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ACounter

Binstance

Cself

Dthis

Attempts:

3 left

💡 Hint

Common Mistakes

Using this to access static properties

Using undefined identifiers

Static methods should access static properties via the class name, here Counter.

4fill in blank

hard

Fill both blanks to declare a static readonly property named MAX_LIMIT of type number with value 100.

Typescript

class Limit {
  [1] readonly [2]: number = 100;
}

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Areadonly

Bstatic

CMAX_LIMIT

Dlimit

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping order of keywords

Using wrong property name

The property must be declared as static readonly MAX_LIMIT to be a static constant.

5fill in blank

hard

Fill all three blanks to declare a static method named increment that increases the static count by 1 and returns the new count.

Typescript

class Counter {
  static count: number = 0;
  static [1](): number {
    Counter.count [2]= 1;
    return [3];
  }
}

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

Aincrement

B+

CCounter.count

D-=

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operator like -=

Returning wrong variable

The method increment adds 1 to Counter.count using += and returns the updated count.