Const enums and optimization in Typescript - Mini Project: Build & Apply

Using Const Enums for Optimization in TypeScript

📖 Scenario: You are building a simple program to represent directions in a game. You want to use enums to name the directions, but also want to make your code run faster by using const enum.

🎯 Goal: Create a const enum for directions, use it in a function to get the opposite direction, and print the result.

📋 What You'll Learn

Create a const enum called Direction with values Up = 0, Down = 1, Left = 2, Right = 3.

Create a function called getOppositeDirection that takes a Direction and returns the opposite Direction.

Use a switch statement inside getOppositeDirection to return the opposite direction.

Call getOppositeDirection with Direction.Left and print the result.

💡 Why This Matters

🌍 Real World

Enums are used in games, apps, and systems to name fixed sets of options like directions, states, or modes. Using <code>const enum</code> makes the code smaller and faster.

💼 Career

Understanding <code>const enum</code> helps you write efficient TypeScript code, which is valuable for frontend and backend development jobs where performance matters.

1

Create a const enum for directions

Create a const enum called Direction with these exact members and values: Up = 0, Down = 1, Left = 2, Right = 3.

Typescript

// Your code here

Need a hint?

Use the const enum syntax and assign the exact values to each direction.

2

Create a function to get the opposite direction

Create a function called getOppositeDirection that takes a parameter dir of type Direction and returns a Direction.

Typescript

const enum Direction {
    Up = 0,
    Down = 1,
    Left = 2,
    Right = 3
}

// Your code here

Need a hint?

Define the function with the correct name, parameter, and return type.

3

Implement the switch to return the opposite direction

Inside the getOppositeDirection function, use a switch statement on dir to return the opposite direction: Up returns Down, Down returns Up, Left returns Right, and Right returns Left.

Typescript

const enum Direction {
    Up = 0,
    Down = 1,
    Left = 2,
    Right = 3
}

function getOppositeDirection(dir: Direction): Direction {
    // Use a switch statement on dir
    // Your code here
}

Need a hint?

Use a switch with cases for each direction and return the opposite.

4

Call the function and print the result

Call getOppositeDirection with Direction.Left and print the result using console.log.

Typescript

const enum Direction {
    Up = 0,
    Down = 1,
    Left = 2,
    Right = 3
}

function getOppositeDirection(dir: Direction): Direction {
    switch (dir) {
        case Direction.Up:
            return Direction.Down;
        case Direction.Down:
            return Direction.Up;
        case Direction.Left:
            return Direction.Right;
        case Direction.Right:
            return Direction.Left;
    }
}

// Your code here

Need a hint?

Use console.log to print the result of calling getOppositeDirection(Direction.Left).