Roadmap

    8 - Exercise III

    Okay, let's do one more exercise to reinforce our learning before we move on to covering more types

    Exercise 3: Arrays and Enums

    Objective:

    • Practice defining and using arrays and enums in TypeScript.

    • Implement a function that processes an array and uses an enum to categorize data.

    • Create a file named exercise3.ts in your src directory.

    • Open exercise3.ts in your text editor and complete the following code:

    ts
    // exercise3.ts
    // Define an enum for task status of 'NotStarted', 'InProgress' and 'Completed'
    ?? TaskStatus {
    	??
    }
    // Define an array of tasks each with a title and status
    let tasks: {???} = [
    	// Add 3 sample tasks with statuses
    	// 1. 'Learn TypeScript' - InProgress
    	// 2. 'Build a TypeScript project' - NotStarted
    	// 3. 'Review TypeScript concepts' - Completed
    ]
    // Define a function that prints the tasks with their statuses
    function printTasks(???: {???}[]): ??? {
    	tasks.forEach(task => {
    		???
    		console.log(??); // print the name and status
    	});
    }
    // Call the function and log the tasks
    printTasks(tasks);

    Check Solution

    • Compile and run your code
    bash
    npx tsc
    node ./dist/exercise3.js

    Your output in the console should be:

    bash
    > node ./dist/exercise3.js
    Learn TypeScript: In Progress
    Build a TypeScript project: Not Started
    Review TypeScript concepts: Completed
    Solution: 
    ts
    // exercise3.ts
    // Define an enum for task status of 'NotStarted', 'InProgress' and 'Completed'
    enum TaskStatus {
      NotStarted = "NotStarted",
      InProgress = "InProgress",
      Completed = "Completed",
    }
    // Define an array of tasks
    let tasks: { title: string; status: TaskStatus }[] = [
      { title: "Learn TypeScript", status: TaskStatus.InProgress },
      { title: "Build a TypeScript project", status: TaskStatus.NotStarted },
      { title: "Review TypeScript concepts", status: TaskStatus.Completed },
    ];
    // Define a function that prints the tasks with their statuses
    function printTasks(tasks: { title: string; status: TaskStatus }[]) {
      tasks.forEach((task) => {
        console.log(`${task.title} - ${task.status}`); // print the name and status
      });
    }
    // Call the function and log the tasks
    printTasks(tasks);