HP OpenVMS DCL Dictionary
F$TYPE
Returns the data type of a symbol. The string INTEGER is returned if
the symbol is equated to an integer, or if the symbol is equated to a
string whose characters form a valid integer.
The string STRING is returned if the symbol is equated to a character
string whose characters do not form a valid integer.
If the symbol is undefined, a null string ("") is returned.
Format
F$TYPE (symbol-name)
Return Value
The string INTEGER is returned if the symbol is equated to an integer,
or if the symbol is equated to a string whose characters form a valid
integer.
If the symbol has been produced by a call to the F$CONTEXT function
with a context type of PROCESS or by a call to the F$PID function, the
string returned is PROCESS_CONTEXT. A symbol retains this type until
F$CONTEXT is called with the symbol and the CANCEL keyword, or until a
null string ("") is returned by a call to F$PID.
Similarly, the return value is the string CLUSTER_SYSTEM_CONTEXT for
symbols created by the F$CSID function.
If the symbol is a context symbol, then the return value will be one of
the types shown in Table DCLI-12.
The string STRING is returned if the symbol is equated to a character
string whose characters do not form a valid integer or whose type is
not a context.
If the symbol is undefined, a null string is returned.
Argument
symbol-name
Specifies the name of the symbol to be evaluated.
Examples
| #1 |
$ NUM = "52"
$ TYPE = F$TYPE(NUM)
$ SHOW SYMBOL TYPE
TYPE = "INTEGER"
|
This example uses the F$TYPE function to determine the data type of the
symbol NUM. NUM is equated to the character string "52".
Because the characters in the string form a valid integer, the F$TYPE
function returns the string INTEGER.
| #2 |
$ NUM = 52
$ TYPE = F$TYPE(NUM)
$ SHOW SYMBOL TYPE
TYPE = "INTEGER"
|
In this example, the symbol NUM is equated to the integer 52. The
F$TYPE function shows that the symbol has an integer data type.
| #3 |
$ CHAR = "FIVE"
$ TYPE = F$TYPE(CHAR)
$ SHOW SYMBOL TYPE
TYPE = "STRING"
|
In this example, the symbol CHAR is equated to the character string
FIVE. Because the characters in this string do not form a valid
integer, the F$TYPE function shows that the symbol has a string value.
| #4 |
$ x = F$CONTEXT("PROCESS",CTX,"USERNAME","SMITH")
$ TYPE = F$TYPE(CTX)
$ SHOW SYMBOL TYPE
TYPE = "PROCESS_CONTEXT"
$ x = F$CONTEXT("PROCESS",CTX,"CANCEL")
$ TYPE = F$TYPE(CTX)
$ SHOW SYMBOL TYPE
TYPE = ""
|
In this example, the F$TYPE function returns the string PROCESS_CONTEXT
because the symbol has been produced by a call to the F$CONTEXT
function with a context type of PROCESS. The symbol returns this type
until F$CONTEXT is called with the symbol and the
selection-item argument value CANCEL.
| 
