What happens if an exception is not caught in JavaScript?

An uncaught exception propagates up the call stack to the global scope, logging an error and halting the current function.

In browsers, uncaught exceptions:

• Trigger the window.onerror handler
• Appear in the browser console
• Stop execution of the current function

In Node.js, uncaught exceptions can crash the process unless handled with process.on('uncaughtException').