关于length 的概念，例如：First = 'Ipswich, England';City = substr(First,1,7)
;那末的length是First的长,还是substr(First,1,7)的结果后Ipswich的长？

还有这到76题，为何说是200呢？而不是从题目中得出来的长？谢谢
76. The following SAS program is submitted:
data work.test;
Author = 'Agatha Christie';
First = substr(scan(author,1,' ,'),1,1);
run;
Which one of the following is the length of the variable FIRST in the output
data set?
A. 1
B. 6
C. 15
D. 200
Answer: D