Roadmap

    4 - Exercise IV

    Exercise: Create an Interface and Implement It in a Function

    Objective:

    • Learn how to define and use interfaces in TypeScript.
    • Implement a function that accepts an object adhering to an interface.

    Instructions:

    1. Create a TypeScript File:

      • Create a file named exercise4.ts in your src directory.
      • Open exercise4.ts in your editor and complete the following code:
    ts
    // exercise4.ts
    // Define an interface for a user that accepts a name, age and email
    interface User {
      ???
    }
    // Define a function that takes a User object and returns this greeting message
    // "Hello, (name)! You are (age) years old and your email is (email).`;
    function greetUser(???): ??? {
      return ???;
    }
    // Create a user object that implements the User type and has
    // name: "Alice",  age: 30, email: "alice@example.com"
    let user ???
    // Call the function and log the result
    console.log(greetUser(user));

    Check Solution

    • Compile and run your code
    bash
    npx tsc
    node ./dist/exercise4.js

    Your output in the console should be:

    bash
    > node ./dist/exercise4.js
    Hello, Alice! You are 30 years old and your email is alice@example.com.
    Solution: 
    ts
    // exercise4.ts
    // Define an interface for a user that accepts a name, age and email
    interface User {
      name: string;
      age: number;
      email: string;
    }
    // Define a function that takes a User object and returns this greeting message
    // "Hello, (name)! You are (age) years old and your email is (email).";
    function greetUser(user: User): string {
      return `Hello, ${user.name}! You are ${user.age} years old and your email is ${user.email}.`;
    }
    // Create a user object that implements the User type and has
    // name: "Alice", age: 30, email: "alice@example.com"
    let user: User = {
      name: "Alice",
      age: 30,
      email: "alice@example.com",
    };
    // Call the function and log the result
    console.log(greetUser(user));