KEYWORD_SET

The KEYWORD_SET function returns a nonzero value if Expression is defined and nonzero or an array, otherwise zero is returned. This function is especially useful in user-written procedures and functions that process keywords that are interpreted as being either true (keyword is present and nonzero) or false (keyword was not used, or was set to zero).

Calling Sequence

Result = KEYWORD_SET( Expression )

Arguments

Expression

The expression to be tested. Expression is usually a named variable.

Example

Suppose that you are writing an IDL procedure that has the following procedure definition line:

PRO myproc, KEYW1 = keyw1, KEYW2 = keyw2

The following command could be used to execute a set of commands only if the keyword KEYW1 is set (i.e., it is present and nonzero):

IF KEYWORD_SET(keyw1) THEN BEGIN

The commands to be executed only if KEYW1 is set would follow.

See Also

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