What will be the output when calling member.getFullName() if getFullName is not added to the prototype?

When calling member.getFullName(), if the getFullName method is not added to the prototype, the method is not defined on the member object. In JavaScript, attempting to call a method that doesn't exist on an object will result in a TypeError.

Specifically, if you try to invoke a method that isn't there, JavaScript can't find the function definition to execute, leading to an error. This is because the object does not recognize the method name as a callable function that can be executed. Therefore, the output would be the TypeError indicating that the method is undefined.

In contrast, the other options don’t accurately represent the situation: a SyntaxError pertains to code structure issues before execution, while returning "Lydia Hallie" or "undefined undefined" implies that the function was somehow found or managed to return values, which isn't applicable when the method is absent.