When working with optional parameters in TypeScript, you may encounter the error message "undefined cannot be assigned to a specific type." This happens because optional parameters can either be `undefined` or of a specified type. To avoid this error, you can use several techniques.
In this tutorial, you will learn how to improve your switch statements and fix certain errors in TypeScript. The article provides tips and tricks, as well as a final code example. Some key takeaways include setting `noImplicitReturns` to `true`, creating a switch case for every valid value, defining a custom return type, and adding a default case to handle unexpected values.