What is the Value equivalent of No selection for a drop down list?

[johnfrytz]

I'm passing the selected values of the drop-down into the parameter.

When the selection is cleared , the parameter displays "<No item selected>".

I'm using the parameter in a calculation. It seems that the calculation is retaining the result for the first condition of the IF-ELSE statement.

Hence I wanted to know the equivalent value for "<No item selected>" to ensure I get the correct results.

[Stu_SAS]

When there is no selection in a single-valued parameter, it produces a missing value. For numeric parameters, it is a dot ., for characters, it is an empty space ' '. 

You can simplify this by using the missing() and notmissing() functions, which will automatically handle both numeric or character values. For example:

if(missing('parameter'p) ) return 1 else 0

If you are on SAS Viya, the isSet() function is a better alternative. isSet() returns True or False (1 or 0) depending on if a parameter has been selected. It can be used to get really great feedback on how someone is using the report. Plus, it works for both single-valued and multi-valued parameters.

if(isSet('parameter'p) ) return 1 else 0

Confirming Parameter Values

In case you ever need to confirm what the value of a parameter actually is in the background, here's a simple trick:

1. Create a new calculated column and simply drag in the parameter:
   
2. Add a list table and add your calculated column as a row
3. Select different values of your parameter to view its raw value