数据线和卡片声明之间有什么区别

Question

I am seeking job on SAS tool. interviewer asked me this question I said no difference, both are used to read internal data but he told there is a difference between cards and datalines statement .

kindly help me to crack this question.

Answer 1

There is no significant difference between the two. CARDS is defined as an alias of DATALINES , and by definition an alias should have identical behavior to the statement it is an alias of.

There is an insignificant difference, which is really simply an undefined behavior; it is explained on page 4 of Andrew Kuligowski's 2007 paper , and related to how cards and datalines have slightly different results when used in a file statement (which they are not intended to be used with). The behavior is slightly different now for datalines in modern SAS (9.4); it gives an error, but a different one from cards . However, it is simply undefined behavior; it would be an absurd thing for an interviewer to expect as an answer.

Your interviewer may have been referring to datalines versus datalines4 , or cards versus cards4 ; those are different, because the latter requires four ; to end instead of one (to allow for the possibility of a semicolon in the data itself).