How TypeScript describes the shapes of JavaScript objects.

Functions are the basic building block of any application, whether they’re local functions, imported from another module, or methods on a class. They’re also values, and just like other values, TypeScript has many ways to describe how functions can be called.

TypeScript provides several utility types to facilitate common type transformations.

Use the compiler flag noImplicitAny to flag any implicit any as an error. When you declare a variable using const, var, or let, you can optionally add a type annotation to explicitly specify the type of the variable: ... TypeScript doesn’t use “types on the left”-style declarations like ...