I bring up TypeScript here because, while we won't be using TypeScript in the examples in this book, some of the examples of ML libraries we examine here are written in TypeScript.
For instance, one example found on the deeplearn.js tutorials page shows code that looks like the following:
const graph = new Graph(); // Make a new input in the graph, called 'x', with shape  (a Scalar). const x: Tensor = graph.placeholder('x', ); // Make new variables in the graph, 'a', 'b', 'c' with shape  and random // initial values. const a: Tensor = graph.variable('a', Scalar.new(Math.random())); const b: Tensor = graph.variable('b', Scalar.new(Math.random())); const c: Tensor = graph.variable('c', Scalar.new(Math.random())
You are welcome to use TypeScript in your own examples as you follow along with this book, however, you will have to update the build process that we set up later to support TypeScript.