Chapter 1: Getting Started with Typescript 4

Our journey of learning design patterns is based on learning their purpose, their structure, and then implementing them using TypeScript 4. We do this mainly for the following reasons:

• To learn our patterns using a modern and concrete programming language such as TypeScript
• To leverage newer concepts of the language as opposed to dated or stereotyped implementations
• To study them, tweak them, or refactor them more carefully using modern best practices

Although TypeScript 4 offers a variety of language features, we are only going to use a small subset of them. For example, we will not discuss how to use namespaces, modules, or mixins; not because the language doesn't offer them, but because they are not very practical when learning about design patterns. The examples in this chapter are self-contained and intended for self-study and as reference implementations. Our goal is to provide material that you can use as a quick reference when you try to use design patterns, or understand the main reasons why or when to apply them in practice.

In this chapter, we are going to cover the following main topics:

• Introducing TypeScript 4
• Understanding TypeScript and JavaScript's relationship
• Installing and using the code examples
• Using VSCode with TypeScript
• Introducing to the Unified Modeling Language (UML)

By the end of this chapter, you will be able to write simple programs in TypeScript, leverage VSCode to compile run tasks, and be able to read basic UML class diagrams.

Note

The links to all the sources mentioned in this chapter, as well as any supplementary reading materials, are provided in the Further reading section, toward the end of this chapter.