April 2018
Beginner to intermediate
426 pages
10h 19m
English
In TypeScript, there are two concepts for interfaces. The first one is related to assigning a type to a variable. Consider the following code:
interface Person {
name: string;
age: number;
}
function printName(person: Person) {
console.log(person.name);
}
The first concept for the TypeScript interface is that an interface is a thing. It is a description of the attributes and methods an object must have.
This allows editors such as VSCode to have autocomplete with IntelliSense, as shown in the following screenshot:

Now, let's try using the printName function:
const john = { name: 'John', age: 21 }; const mary = { name: 'Mary', age: ...