Promises & then/catch

promise
  .then(value => console.log(value))
  .catch(error => console.error(error))
  .finally(() => cleanup());

To handle successful results
To handle errors
To execute code regardless of success or failure
The finally() method executes code regardless of the Promise's outcome. Key features: 1) Runs after either then() or catch() completes, 2) Perfect for cleanup operations like closing connections or files, 3) Doesn't receive any arguments from the Promise chain, 4) Returns a Promise, allowing further chaining if needed, 5) Executes even if previous handlers throw errors, 6) Helps avoid code duplication in then() and catch() blocks.
To end the Promise chain