The "Current" tab of the Data Viewer includes a "Type" column. However, the information displayed here is often less than helpful. For example, $customer_id is labeled with a type of "Local Variable".
The reported information should be improved to indicate the variable's type: Number, Text, Date, etc. Maybe this would replace the current text with something such as "Local Variable, Number", or an additional column would suffice. Maybe retooling the columns would be more appropriate: "Reference Type: Field, Local Variable, etc" and "Data Type: Number, Text, Date, etc."
The following code will assign two different variables that are indistinguishable in the data viewer:
Set Variable [ $i ; Value: 10 ]
Set Variable [ $j ; Value: "10" ]
These variables are different types. This can result in run-time bugs that are very hard to identify. To demonstrate the problem, and prove that the variables are in fact different, follow that code with:
Set Variable [ $test_one ; 2 > $i ]
Set Variable [ $test_two ; 2 > $j ]
There are good reasons to preserve current variable typing capability, we just need better visibility to the data. This request is an excellent companion to DataType ( data ) function which provides access to the same type of information in the calc engine.