Batch nested If statement error with not defined variables

Question

I have a problem with a simple batch script. See:

SET TEST=
IF NOT DEFINED TEST ( 
    SET "TEST=1"
) ELSE (
    IF %TEST% LSS 1 ( SET "TEST=1")
)

Here the if in the else branch failes, because the variable TEST ist not defined. But the else branch even shouldn't been executed if the variable TEST isn't defined!? What is here the problem? (I knew, that this code would work, if I leave the else and write it under the if statement, but then this code get's executed every time.) How to solve this problem?

THX.

npocmaka · Accepted Answer · 2016-02-08 11:23:50Z

3

Magoo's answer will prevent the error but it will lead to alphabetical comparison instead of numerical.I think it will be better to use delayed expansion and one additional if defined statement :

setlocal enableDelayedExpansion
SET "TEST="
IF NOT DEFINED TEST ( 
    SET "TEST=1"
) ELSE (
    if defined test IF !TEST! LSS 1 ( SET "TEST=1")
)

answered Feb 8, 2016 at 11:23

npocmaka

57.8k19 gold badges162 silver badges199 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Magoo · Accepted Answer · 2016-02-08 10:25:56Z

2

The entire statement is parsed that is, examined for syntactic correctness before it is executed.

The parser finds

) ELSE (
    IF LSS 1 ( SET "TEST=1")
)

and objects because 1 is not a comparison operator.

) ELSE (
    IF "%TEST%" LSS "1" ( SET "TEST=1")
)

should fix the problem.

answered Feb 8, 2016 at 10:25

Magoo

80.8k8 gold badges68 silver badges92 bronze badges

2 Comments

npocmaka Over a year ago

but this will force an alphabetical comparison instead of numerical

Magoo Over a year ago

@npocmaka :: true, but that won't be a problem unless the variable ever exceeds 9 or is negative. In all probability, and the absence of information to the contrary, the variable is likely to be set to 0 or 1 or not-set-at-all. Personally, I'd use a setting of nothing or something which allows if defined to work with run-time variables within a block statement.

Collectives™ on Stack Overflow

Batch nested If statement error with not defined variables

2 Answers 2

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related