Ques 45 : What is the difference between INTCK and INTNX function in SAS ?
Ans : In SAS, INTCK function calculates the number of interval between to dates while INTNX function calculates the date of a given number of intervals.
Suppose today is '01JAN2015' then by INTCK we can calculate that there are '364' days in between today and '31DEC2015'.
While if we want to get the date just after '364' days from today (01JAN2015) then by INTNX the result would be '31DEC2015'.
DATA DSN;
FORMAT INTNX1 date9.;
INTCK1=INTCK('Days','01JAN2015'd,'31DEC2015'd);
INTNX1=INTNX('Days','01jan2015'd,364);
Run;
Ques 46 : Which SAS Statement is more useful or efficient : WHERE or IF ?
Ans : WHERE statement is more useful in SAS in comparison to IF statement. We can use WHERE statement in Data Step as well as with SAS Procedures but we can not use IF statement in SAS Procedures.
There are several useful operators, we can use with WHERE statement given as : 'LIKE', 'CONTAINS', 'IS NULL', 'IS MISSING', 'BETWEEN AND' and so on...
* If we use more than one 'WHERE' statements condition on same variable in a same data step or proc step, then last WHERE statement will overwrite on all previous ones
* If we use more than one 'IF' statements condition on same variable in a same data step, then there would be no execution but it could get execute by using 'OR' or 'AND'
* We can not use any automatic variables created by data step (FirstDot, LastDot ,_N_ , _ERROR_) in a 'WHERE' expression
Ques 47 : What is the SAS valid date range and what would happen if someone passes the date which is outside of SAS date range ?
Ans : We are familiar with a date '01JAN1960' which is just to perform calculation on dates into SAS.
SAS dates are valid from '01JAN1582' AD to '31DEC20000' AD.
If we pass any date prior or after of valid dates then values would get truncated.
Ques 48 : What are the various methods to combine SAS data sets ?
Ans : There are several ways to combine SAS datasets. Some methods are given below :
(A) Concatenate (B) Interleave (C) Merge (D) Update (E) Modify
Ques 49 : What would happen if we use same variable for DROP and KEEP statement in SAS ?
Ans : If same variable is specified in both 'DROP=' and 'KEEP=' statement then variable would get dropped.
Ques 50 : While concatenation of SAS dataset, which method is faster than other : PROC APPEND or SET Statement ?
Ans : SAS Procedure PROC APPEND concatenates much faster than the SET Statement because Proc Append does not process the observations from the base data set.
* We can use any number of datasets with SET statement but for PROC APPEND we can use only two datasets
* We can specified upto 50 SAS datasets in a single SET statement
Ans : In SAS, INTCK function calculates the number of interval between to dates while INTNX function calculates the date of a given number of intervals.
Suppose today is '01JAN2015' then by INTCK we can calculate that there are '364' days in between today and '31DEC2015'.
While if we want to get the date just after '364' days from today (01JAN2015) then by INTNX the result would be '31DEC2015'.
DATA DSN;
FORMAT INTNX1 date9.;
INTCK1=INTCK('Days','01JAN2015'd,'31DEC2015'd);
INTNX1=INTNX('Days','01jan2015'd,364);
Run;
Ques 46 : Which SAS Statement is more useful or efficient : WHERE or IF ?
Ans : WHERE statement is more useful in SAS in comparison to IF statement. We can use WHERE statement in Data Step as well as with SAS Procedures but we can not use IF statement in SAS Procedures.
There are several useful operators, we can use with WHERE statement given as : 'LIKE', 'CONTAINS', 'IS NULL', 'IS MISSING', 'BETWEEN AND' and so on...
* If we use more than one 'WHERE' statements condition on same variable in a same data step or proc step, then last WHERE statement will overwrite on all previous ones
* If we use more than one 'IF' statements condition on same variable in a same data step, then there would be no execution but it could get execute by using 'OR' or 'AND'
* We can not use any automatic variables created by data step (FirstDot, LastDot ,_N_ , _ERROR_) in a 'WHERE' expression
Ques 47 : What is the SAS valid date range and what would happen if someone passes the date which is outside of SAS date range ?
Ans : We are familiar with a date '01JAN1960' which is just to perform calculation on dates into SAS.
SAS dates are valid from '01JAN1582' AD to '31DEC20000' AD.
If we pass any date prior or after of valid dates then values would get truncated.
Ques 48 : What are the various methods to combine SAS data sets ?
Ans : There are several ways to combine SAS datasets. Some methods are given below :
(A) Concatenate (B) Interleave (C) Merge (D) Update (E) Modify
Ques 49 : What would happen if we use same variable for DROP and KEEP statement in SAS ?
Ans : If same variable is specified in both 'DROP=' and 'KEEP=' statement then variable would get dropped.
Ques 50 : While concatenation of SAS dataset, which method is faster than other : PROC APPEND or SET Statement ?
Ans : SAS Procedure PROC APPEND concatenates much faster than the SET Statement because Proc Append does not process the observations from the base data set.
* We can use any number of datasets with SET statement but for PROC APPEND we can use only two datasets
* We can specified upto 50 SAS datasets in a single SET statement
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