Hands-On Full Stack Web Development with Angular 6 and Laravel 5

Declaring an interface

Interfaces are our allies when we use TypeScript, since they do not exist in pure JavaScript. They are an efficient way of grouping and typing variables, ensuring that they are always together, maintaining consistent code.

Let's look at a practical way to declare and use an interface:

1. In your text editor, create a new file called band-interface.ts, and add the following code:

interface Band {    name: string,    total_members: number}

To use it, assign the interface to a function type, as in the following example.

2. Add the following code right after the interface code, in the band-interface.ts file:

interface Band {    name: string,    total_members: number}function unknowBand(band: Band): void { console.log("This band: " ...