Installing Node.JS

It is common to write a function where the return data type is related to the data type(s) of the parameters passed to the functions. Let’s look at an example of this: This function will return the first element of an array. However, it uses the any data type to allow for any type of…

You will need to install the TypeScript engine for you to use TypeScript. This is because your TypeScript code must be converted into JavaScript, so it needs a program called a transpiler to do the conversion to JavaScript so that a browser can run it. What does a Transpiler Actually Do? A transpiler is not…

We’ve already seen the standard data types in JavaScript and TypeScript. However, JavaScript allows for class, and we want to therefore be able to define a custom data type within TypeScript. Since JavaScript supports classes and object-oriented programming, so does TypeScript. You can explicitly describe this object’s shape using an interface declaration. Then, to define an object…

We’ve already briefly looked at classes in TypeScript and classes in JavaScript, so let’s delve a little deeper now. Since TypeScript is just JavaScript, with some added on bits, we can create a class as we normally would with the adding of types as you see below. However, we can overload our constructors to see…

Once we’ve created our first TypeScript file, we need to convert it to JavaScript if we want our browsers (or Node.JS) to run it. There are several online sandbox tools to let you write code, but they won’t convert it to JavaScript, at least none that I’ve found yet. To set it up, you will…

The tsconfig.json file specifies the root files and the compiler options required to compile a TypeScript project. So presence of a tsconfig.json file in a directory indicates that the directory is the root of a TypeScript project. Without that file, the compiler will continue to move up the directory hierarchy to fine the config file. There is also a…