Static members with types in Typescript - Mini Project: Build & Apply

Static members with types

📖 Scenario: You are creating a simple class to keep track of how many times a certain action happens across all instances.

🎯 Goal: Build a TypeScript class with a static member that counts how many times a method is called on any instance.

📋 What You'll Learn

Create a class called ActionCounter

Add a static number property called count initialized to 0

Add a method called performAction that increases count by 1

Use proper TypeScript types for the static member and method

Print the static count after calling performAction multiple times

💡 Why This Matters

🌍 Real World

Static members are useful to keep track of data shared across all objects, like counting total users logged in or tracking global settings.

💼 Career

Understanding static members helps in designing classes that manage shared data efficiently, a common task in software development.

1

Create the class with a static count property

Create a class called ActionCounter with a static property count of type number initialized to 0.

Typescript

class ActionCounter {
  // Your code here
}

Need a hint?

Use static keyword before the property name and specify the type number.

2

Add the performAction method

Inside the ActionCounter class, add a method called performAction that increases the static count by 1.

Typescript

class ActionCounter {
  static count: number = 0;

  // Your code here
}

Need a hint?

Use ActionCounter.count inside the method to access the static property.

3

Create instances and call performAction

Create two instances of ActionCounter named first and second. Call performAction once on first and twice on second.

Typescript

class ActionCounter {
  static count: number = 0;

  performAction(): void {
    ActionCounter.count += 1;
  }
}

// Your code here

Need a hint?

Create instances with new ActionCounter() and call the method with dot notation.

4

Print the static count

Print the value of the static count property of ActionCounter using console.log.

Typescript

class ActionCounter {
  static count: number = 0;

  performAction(): void {
    ActionCounter.count += 1;
  }
}

const first = new ActionCounter();
const second = new ActionCounter();

first.performAction();
second.performAction();
second.performAction();

// Your code here

Need a hint?

Use console.log(ActionCounter.count) to print the static count.