TAG_NAMES

The TAG_NAMES function returns a string array containing the names of the tags in a structure expression. It can also be used to determine the expression's structure name (if the structure has a name).

Calling Sequence

Result = TAG_NAMES( Expression )

Arguments

Expression

The structure expression for which the tag names are returned. This argument must be of structure type. TAG_NAMES does not search for tags recursively, so if Expression is a structure containing nested structures, only the names of tags in the outermost structure are returned.

Keywords

STRUCTURE_NAME

Set this keyword to return a scalar string that contains the name of the structure instead of the names of the tags in the structure. If the structure is "anonymous", a null string is returned.

Example

Print the names of the tags in the system variable !P by entering:

PRINT, TAG_NAMES(!P)

IDL prints:

BACKGROUND CHARSIZE CHARTHICK CLIP COLOR FONT LINESTYLE MULTI

NOCLIP NOERASE NSUM POSITION PSYM REGION SUBTITLE SYMSIZE T

T3D THICK TITLE TICKLEN CHANNEL

PRINT, TAG_NAMES(!P, /STRUCTURE_NAME) ; Print the name of the structure in the system variable !P.