How can a university change all phone numbers with the 565 exchange to 765 using SAS programming?
Final Answer:After careful evaluation of the provided code snippets, the correct statement to effectively change the values of the Phone variable from the '565' exchange to '765' in the dataset Mylib.university is Option B. This option accurately utilizes the `substr` function to modify the first three digits of the Phone variable based on the specified condition, ensuring the correct exchange change while preserving the rest of the phone number intact.
Explanation:
In the given code, Option B utilizes `substr` function correctly to replace the initial three digits of the Phone variable. It correctly identifies the Exchange, represented by the first three digits of the Phone number, and uses an `if` statement to check if the Exchange is '565'. If true, it then replaces the first three characters of the Phone variable with '765', effectively changing the exchange as required. This method employs the correct syntax and logic to modify the phone numbers accurately.
Within the provided options, Option A tries to assign a new value to the result of the `scan` function, which doesn’t change the original variable. Option C incorrectly assigns the value of '765' to the entire Phone variable, discarding the rest of the number. Option D also wrongly assigns the value '765' to only the first three characters of the Phone variable, not considering the specific numbers in the dataset.
Option B stands out as the correct choice as it directly alters the initial three digits of the Phone variable based on the condition provided, ensuring that only the necessary part of the number is replaced while preserving the rest of the phone number intact (option B).