望高人指点一下

1,有个题选 sum(sum(A,B)) 这个函数有什么用?

2, data sasuser.ranch sasuser.condo/view=sasuser.ranch;  *这个 view 有什么作用呢?

    set sasuser.houses;

    if style='RANCH' then output sasuser.ranch;

    else if style='CONDO' then output sasuser.condo;

    run;

3 the following SAS program is submitted:

%macro cols1;

name age;

%mend;

%macro cols2;

height weight;

%mend;

proc print data=sashelp.class;

???

run;

which statement successfully completes the programa and produces a report?

1, var %cols2 %cols1;       2,var height %col1;

3,var %cols1 height;        4,var %cols1 %cols2 height;                       answer:  2                  i don't know why

4. the following SAS program is submitted:data temp;

length a 1 b 3 x;

infile 'file reference';

input a b x ;

run;

what is the result ?       答案是 the data set TEMP is not created because variable A has an invalid length.

5 hash object 是什么??