Finding Variable Data Type

DTYPE E K

Use DTYPE to determine the data type of a column or constant (E), and store the results in a constant (K).

Values returned by DTYPE:

0 = text

1 = real numbers

2 = integers

3 = date/time

10 = empty

DTYPE is often used with free variables (and the MFREE and MTYPE commands) in cases where the macro must be flexible enough to respond to a variety of possible inputs.

DTYPE is very useful when parts of your macro only work on some types of data. For example, you may have a subcommand of your local macro that lets the user specify a title for a graph; DTYPE can tell you if the user specified a text string or a number. Or, perhaps a part of your macro requires an integer; DTYPE could tell you if a variable was not an integer, allowing your macro to convert the real number to an integer.

Note	DTYPE only works as a command. It does not work with IF or LET, for example.

Example of a macro that uses DTYPE

TELLDATA tells a user the data type of the variable specified when the macro is invoked. Here is the complete code:

MACRO

TELLDATA X

MFREE X

MCONSTANT Vartype

DTYPE X Vartype

IF Vartype = 0

NOTE Variable is text

ELSEIF Vartype = 1

NOTE Variable is real number

ELSEIF Vartype = 2

NOTE Variable is integer

ELSEIF Vartype = 3

NOTE Variable is date/time

ELSEIF Vartype = 10

NOTE Variable is empty

ENDIF

ENDMACRO