topic Re: Let scope in QlikView

Let scope

Fri, 29 Jul 2016 15:51:37 GMT

I have a loop in my script, something like below:

For i = 0 TO 10

LET expr = i * 2;

NEXT i

I would like to know whether expr variable created within loop is available outside loop for, for example, could I do something like below?

or I need to declare variable expr before loop for using SET sentence?

For i = 0 TO 10

LET expr = i * 2;

NEXT i

LET another_expr = expr; // What is the value for expr here? 20?

Re: Let scope

Anil_Babu_Samineni — Fri, 29 Jul 2016 16:01:56 GMT

Might be from 0 to 9 The values are not correct. That's why the loop working on 10th Value

10 * 2 = 20

Re: Let scope

jpenuliar — Fri, 29 Jul 2016 16:07:15 GMT

Hi Tony TP,

variable expr is not private to the for loop.

That's why, you can perform transferring value of expr to another_expr.

which is 20 at the end of For Next.

Its interesting to run the loop in debug to follow the iterations.

regards,

Re: Let scope

Clever_Anjos — Fri, 29 Jul 2016 16:33:15 GMT

Qlikview variables are always global scope.

in your case, last value for expr = 10 * 2 = 20

Re: Let scope

maxgro — Fri, 29 Jul 2016 20:34:07 GMT

try this, I added some trace to your "for loop"

For i = 0 TO 10

LET expr = i * 2;

trace i=$(i) expr=$(expr);

NEXT i

LET another_expr = expr;

trace another_expr=$(another_expr);

and you get this result

i=0 expr=0

i=1 expr=2

i=2 expr=4

i=3 expr=6

i=4 expr=8

i=5 expr=10

i=6 expr=12

i=7 expr=14

i=8 expr=16

i=9 expr=18

i=10 expr=20

another_expr=20

I would like to know whether expr variable created within loop is available outside loop for, for example, could I do something like below?

yes

or I need to declare variable expr before loop for using SET sentence?

LET another_expr = expr; // What is the value for expr here? 20?

yes

Re: Let scope

Mon, 01 Aug 2016 19:20:56 GMT

Thanks for your example and for your detailed explanation