This lesson's interactive features are locked, please to keep using them

Interfaces

Click to play video

As it turns out, there are two ways to define object types: the type keyword (as we've seen with type aliases) and interfaces:

type Superhero = {
  name: string;
  powers: string[];
  isAvenger: boolean;
};

interface Superhero {
  name: string;
  powers: string[];
  isAvenger: boolean;
}

I'm a huuuuge fan of having multiple ways to do the same things in a language... /s

In 9/10 scenarios, they work the same way, but there are a few key differences that we'll cover in this chapter. For now, just know that I recommend using type in most cases, but there are a few scenarios where interface is the better choice, which we'll talk about later.

Assignment

We need a way to get analytics on each of Support.ai's support sessions. Each session contains basic info about the session as well as the customer's feedback on the interaction.

Create and export an interface named UserFeedback with the following properties and types:
- rating - number
- comment - string
Create and export an interface named SupportSession with the following properties and types:
- id - string
- startedAt - number (unix timestamp, seconds)
- endedAt - number (unix timestamp, seconds)
- feedback - UserFeedback
Complete the getSessionDuration function. It takes a SupportSession as a parameter and returns the duration of the session in seconds.