Final answer:
The results of eval cannot be directly written to an existing field; eval returns the result which must then be assigned to a field. The answer is b) False.
Step-by-step explanation:
The question pertains to the evaluation of expressions in a programming context, particularly whether the results of eval can be written to an existing field. The answer to this question is b) False.
In most programming languages, the eval function is used to evaluate a string as a piece of code. However, using eval to directly modify the contents of an existing field (or variable) is not its primary purpose. Instead, eval typically returns the result of the evaluated expression, which can then be assigned to a field or variable by the programmer in a separate step. It is crucial to use eval with caution, as it can lead to security vulnerabilities if not handled properly, especially when dealing with user-generated input.