In our gym diary application, we now need the workout list page component, DiaryComponent, to communicate with the list item component, EntryItemComponent. The simplest way to accomplish this communication is with Angular’s Property Binding concept.…
With this command, the Angular CLI will create a folder with the following four files in addition to updating the diary module with the new component. In the entry-item.component.ts file, the Angular CLI created the…
The main building blocks of an Angular application are the components. It is by using them that we assemble our user interfaces and define the flow of the experience. In Angular architecture, components organize an…
In the development of TypeScript applications, we may have situations where we do not know which type of parameter we are going to receive, such as the return of an API. What is trafficked can…
Now that we know the TypeScript inference mechanism, we can understand another feature present in it, type guards. Let’s consider these in the following example:function getDiscount(value: string | number) { if (typeof value === “number”) { return…
In TypeScript, by default, all function and method parameters are required and checked by the transpiler.If any parameter is optional, we can define it in the type it represents, as in the following example: function…
One of the best ways used by TypeScript to improve the developer experience in Angular application development is through the ability to type parameters and return functions and methods. Both for developers who create libraries…
The last way to type a variable that we will see in this chapter is the simplest one, which is to create type aliases. Like interfaces, type aliases only exist in TypeScript, and we can…
In TypeScript, we have another way of typifying the structure of an object called an interface. The following example demonstrates its use: export interface Animal {species: string;kingdom: string;class: string;} To declare an interface, we use…
Building on our knowledge of basic types, let’s now create more complex data types. The first one we’re going to explore is classes. An essential element of object-oriented programming, the class represents a model, which…