InstanceType type in Typescript - Mini Project: Build & Apply

Using the InstanceType Type in TypeScript

📖 Scenario: You are working on a TypeScript project where you want to create an instance of a class dynamically and use its type safely.

🎯 Goal: Learn how to use the InstanceType utility type to get the instance type of a class constructor.

📋 What You'll Learn

Create a class called Car with a property model of type string and a method drive that returns a string.

Create a type alias called CarInstance using InstanceType with the typeof Car.

Create a variable called myCar of type CarInstance and assign it a new instance of Car.

Print the result of calling myCar.drive().

💡 Why This Matters

🌍 Real World

Using <code>InstanceType</code> helps when you want to work with instances of classes dynamically and keep your code type-safe.

💼 Career

Understanding utility types like <code>InstanceType</code> is important for writing robust TypeScript code in professional development.

1

Create the Car class

Create a class called Car with a constructor that takes a model parameter of type string and assigns it to a public property model. Add a method called drive that returns the string `Driving the ${this.model}`.

Typescript

// Your code here

Need a hint?

Use class Car with a constructor and a method drive that returns a template string.

2

Create the CarInstance type alias

Create a type alias called CarInstance using InstanceType with typeof Car as the parameter.

Typescript

class Car {
    constructor(public model: string) {}
    drive() {
        return `Driving the ${this.model}`;
    }
}

// Your code here

Need a hint?

Use type CarInstance = InstanceType<typeof Car> to get the instance type.

3

Create a variable of type CarInstance

Create a variable called myCar of type CarInstance and assign it a new instance of Car with the model 'Tesla'.

Typescript

class Car {
    constructor(public model: string) {}
    drive() {
        return `Driving the ${this.model}`;
    }
}

type CarInstance = InstanceType;

// Your code here

Need a hint?

Use const myCar: CarInstance = new Car('Tesla') to create the instance.

4

Print the drive method output

Write a console.log statement to print the result of calling myCar.drive().

Typescript

class Car {
    constructor(public model: string) {}
    drive() {
        return `Driving the ${this.model}`;
    }
}

type CarInstance = InstanceType;

const myCar: CarInstance = new Car('Tesla');

// Your code here

Need a hint?

Use console.log(myCar.drive()) to show the output.