Question

If I’m passing an object to a case statement, and there is a case where it is undefined, can I handle that case? If so then how? If its not possible, then what is the best practice for handling an undefined case for a switch?

Answer 1

Add a case for undefined.

case undefined:
  // code
  break;

Or, if all other options are exhausted, use the default.

default:
  // code
  break;

Note: To avoid errors, the variable supplied to switch has to be declared but can have an undefined value. Reference this fiddle and read more about defined and undefined variables in JavaScript.