The Any datatype – PB Docs 2021

General information

PowerBuilder also supports the Any datatype, which can hold any kind
of value, including standard datatypes, objects, structures, and arrays. A
variable whose type is Any is a chameleon datatype — it takes the
datatype of the value assigned to it.

Declarations and assignments

You declare Any variables just as you do any other variable. You can
also declare an array of Any variables, where each element of the array
can have a different datatype.

You assign data to Any variables with standard assignment
statements. You can assign an array to a simple Any variable.

After you assign a value to an Any variable, you can test the
variable with the ClassName function and find out the actual
datatype:

These rules apply to Any assignments:

Restrictions

If the value of a simple Any variable is an array, you cannot access
the elements of the array until you assign the value to an array variable
of the appropriate datatype. This restriction does not apply to the
opposite case of an array of Any variables — you can access each Any
variable in the array.

If the value of an Any variable is a structure, you cannot use dot
notation to access the elements of the structure until you assign the
value to a structure of the appropriate datatype.

After a value has been assigned to an Any variable, it cannot be
converted back to a generic Any variable without a datatype. Even if you
set it to NULL, it retains the datatype of the assigned value until you
assign another value.

Operations and expressions

You can perform operations on Any variables as long as the datatype
of the data in the Any variable is appropriate to the operator. If the
datatype is not appropriate to the operator, an execution error
occurs.

For example, if instance variables ia_1 and ia_2 contain numeric
data, this statement is valid:

If ia_1 and ia_2 contain strings, you can use the concatenation
operator:

However, if ia_1 contained a number and ia_2 contained a string, you
would get an execution error.

Datatype conversion functions

PowerScript datatype conversion functions accept Any variables as
arguments. When you call the function, the Any variable must contain data
that can be converted to the specified type.

For example, if ia_any contains a string, you can assign it to a
string variable:

If ia_any contains a number that you want to convert to a string,
you can call the String function:

Other functions

If a function’s prototype does not allow Any as a datatype for an
argument, you cannot use an Any variable without a conversion function,
even if it contains a value of the correct datatype. When you compile the
script, you get compiler errors such as Unknown function or Function not
found.

For example, the argument for the Len function refers to a
string column in a DataWindow, but the expression itself has a type of
Any:

This works because the string value of the Any expression is
explicitly converted to a string:

Expressions whose datatype is Any

Expressions that access data whose type is unknown when the script
is compiled have a datatype of Any. These expressions include expressions
or functions that access data in an OLE object or a DataWindow
object:

The objects these expressions point to can change so that the type
of data being accessed also changes.

Expressions that refer to DataWindow data can return arrays and
structures and arrays of structures as Any variables. For best
performance, assign the DataWindow expression to the appropriate array or
structure without using an intermediate Any variable.

Overusing the Any datatype

Do not use Any variables as a substitute for selecting the correct
datatype in your scripts. There are two reasons for this: