For instance, making a React app essentially consists of describing how the DOM should look using JSX, and letting React mutate the DOM in a performant way under the hood. The big idea is to separate the code describing what needs to be done from the code that interprets this description in order to produce side effects. Yet, Javascript and TypeScript weren’t designed for this paradigm, and these languages are lacking a very important piece of the puzzle: declarative code branching.ĭeclarative programming essentially consists of defining expressions rather than statements - that is, code that evaluates to a value. Today, we truly live in a declarative programming world!

Libraries such as XState, Redux, and many more let you declaratively manage your application state to unlock the same benefits: writing code that is easier to understand, modify and test. It’s not only the user interface - state management libraries as well have been taking a declarative turn. It has been widely adopted by the industry, and now that we have realized how much easier it is to reason about declarative code and how many bugs are ruled out by embracing this paradigm, there is simply no going back. React shifted our mindsets from imperatively manipulating the DOM to declaratively expressing what the DOM should look like for a given state. In the past few years, frontend development has become increasingly declarative.

Javascript pattern matching