SAS是否使用Java之类的数据结构

Question

Java has the concept of data structures. Each data structure has its own advantages and disadvantages. In SAS, all data always goes into a 'data' step?

What java Collection does the 'data' in SAS compare to? Is it an Array, a List? Seems more like a Hashmap?

Is it even fair to draw this comparison?

Answer 1

SAS data can be likened to a tables in any typical RDBMS. So probably a two dimensional array would be the fairest comparison. ie. a table structure.

These structures can be operated on by all sorts of procedures (eg proc sort , proc sql , etc.) or the data step.

It's definitely not a hashmap as data in SAS does not require a unique key (as implemented by hashmaps).

If you wanted a different data structure such as a graph structure containing nodes, and edges, etc. then SAS does not really provide a mechanism to represent them.

Answer 2

http://www.ats.ucla.edu/stat/sas/library/SASRead_os.htm says

You can think of a data set as a two-dimensional table

which IMO means that nothing directly comparable comes with standard Java. You can build similar (functionally equivalent) data structures with lists of lists or other collection of collection compositions.

Answer 3

I don't think there's a direct comparison to a Java collection type, but articles I've seen loosely correlate it to an array.

https://support.sas.com/documentation/cdl/en/lrcon/62955/HTML/default/viewer.htm#a003252712.htm

Only one-dimensional array parameters are supported. However, it is possible to pass multidimensional array arguments by taking advantage of the fact that the arrays are passed in row-major order. You must handle the dimensional indexing manually in the Java code--that is, you must declare a one-dimensional array parameter and index to the subarrays accordingly.