Multiple interface extension in Typescript - Mini Project: Build & Apply

Multiple Interface Extension in TypeScript

📖 Scenario: Imagine you are creating a simple system to describe different types of vehicles. Each vehicle has some common features, but some vehicles have extra features. You want to use TypeScript interfaces to organize these features clearly.

🎯 Goal: You will build TypeScript interfaces where one interface extends multiple other interfaces. This helps combine features from different sources into one interface.

📋 What You'll Learn

Create interfaces with specific properties

Use multiple interface extension

Create an object that uses the extended interface

Print the combined object properties

💡 Why This Matters

🌍 Real World

Using multiple interface extension helps organize complex data models in software, like describing vehicles with many features.

💼 Career

Understanding interface extension is important for TypeScript developers to write clean, reusable, and scalable code.

1

Create base interfaces

Create two interfaces called Engine and Wheels. The Engine interface should have a property horsepower of type number. The Wheels interface should have a property count of type number.

Typescript

# Create interface Engine with horsepower: number
# Create interface Wheels with count: number

Need a hint?

Use the interface keyword to create interfaces. Each property needs a name and a type.

2

Create an interface that extends both Engine and Wheels

Create an interface called Car that extends both Engine and Wheels. Add a new property brand of type string to Car.

Typescript

# Create interface Car that extends Engine and Wheels
# Add brand: string property to Car

Need a hint?

Use extends with a comma to extend multiple interfaces.

3

Create a variable of type Car

Create a variable called myCar of type Car. Assign it an object with horsepower 150, count 4, and brand "Toyota".

Typescript

# Create variable myCar of type Car with properties

Need a hint?

Use const to create the variable and assign an object with all required properties.

4

Print the car details

Write a console.log statement to print the string: "My Toyota car has 150 horsepower and 4 wheels." using the properties of myCar.

Typescript

# Print the car details using console.log

Need a hint?

Use a template string with backticks and ${} to insert variables inside the string.