A lightning-fast crash course on JavaScript, the world’s most popular programming language. From its 1995 origins as Mocha in ...

Asynchronous programming in JavaScript leverages features like callbacks, promises and async/await to sidestep this issue by allowing other code to run in the meantime.

Using callback-passing for asynchronous actions does not compose well and creates complex flows of passing callbacks around. The JavaScript community has produced several libraries to cope with this.