topic LOOP & LEAVE; in SAS Programming

LOOP & LEAVE;

apple — Sun, 20 Dec 2015 06:50:31 GMT

Using SAS 7.1.

I don't understand how the below loop works.

Does the "Leave" indicate the loop will be exited once a missing TYP is found?

For Eg if I=14 --> TYP(14)=missing, then IK=15.

It won't continue to see if TYP(13), TYP(12), ...TYP(1), has missing values. Thank you

DO I = 15 TO 1 BY -1;

IF MISSING(TYP{I}) THEN DO;

IK = I + 1;

LEAVE;

END;

Re: LOOP & LEAVE;

LinusH — Sun, 20 Dec 2015 07:22:05 GMT

Documentation is quite clear :
"You can use the LEAVE statement to exit a DO loop or SELECT group prematurely based on a condition."
So, yes.

Re: LOOP & LEAVE;

FreelanceReinh — Sun, 20 Dec 2015 12:21:26 GMT

It should be noted that the LEAVE statement is not valid within a non-looping/non-iterative DO-END block (an error message would occur!), unless this block is in turn located in a SELECT-END block or in a DO loop (as in your example).

In the latter situation, both the remaining iterations of the DO loop and the statements following the LEAVE statement in the DO-END block (if any) are skipped.

In your example (with missing TYP{14} and provided that TYP{15} is not missing) IK is set to 15 and no further IF-checks are performed.