Correct Use of Variable Declaration in the Modeler

Hello all,

I am looking for information on the correct use of expressions, for example as shown in the screenshot below. I mean the correct spelling, for example what does the dollar sign mean?

Another example: How can I specify the expression in the Modeller so that the variable I later use in the Execution must be a string?

Unfortunately I did not find anything on the Camunda page.

Thank you in advance,

Hi @felmmd,

main entry into the expression language documentation is here:

The implementation is based on a JEE standard, defined here:

Your expression evaluates a variable, it didn’t define any. Position has to exist before the evaluation and has to be an integer. (Maybe, Distance is a better term for your use case).

You can also invoke a bean and call a method here with the position of the customer and the truck and calculate the distance in this method.

Hope this helps, Ingo

Hello Ingo,

thanks for your detailed answer, yes it helped. In general, there is no guide for the Modeler right?

I always need a long time to understand the functionality of the individual fields. Maybe you can help me with another problem: How can I execute the multi instance, if I don’t know the exact number of instances before (so the field Loop Cardinality should be variable until runtime). What can I put in the Collection field?

Again, thank you very much,