Velocity is interpreting int i = 0 as boolean false

Question

If I check var int i = 0 for existing I get wrong result:

#if($i)
  <output>$i</output>
#end

results in:

i not defined --> no output
i = 0         --> no output
i = 1         --> <output>1</output>

How can I tell velocity to consider value 0 as defined?

i not defined --> no output
i = 0         --> <output>0</output>
i = 1         --> <output>1</output>

score 1 · Accepted Answer · answered Dec 21 '20 at 12:50

1

You can check with an operator

#if($i >= 0)
  <output>$i</output>
#end

answered Dec 21 '20 at 12:50

Ori Marko

It does not throw an exception when $i is not defined – Hasan Tuncay Dec 21 '20 at 13:11
I would appreciate if velocity whould add a command like "exists". #ifexists($i) – Hasan Tuncay Dec 21 '20 at 13:38
@HasanTuncay see if `!` helps https://stackoverflow.com/questions/4825636/velocity-is-a-any-way-to-check-if-variable-is-defined – Ori Marko Dec 21 '20 at 13:39

1 Answers1