Argument Keywords in Intrinsic Procedures

For all intrinsic procedures, the arguments shown are the names you must use as keywords when using the keyword form for actual arguments. For example, a reference to function CMPLX(X, Y, KIND) can be written as follows:

Using positional arguments:  CMPLX(F, G, L) 
Using argument keywords: 1  CMPLX(KIND=L, Y=G, X=F)
1 Note that argument keywords can be written in any order.

Some argument keywords are optional (denoted by square brackets). The following describes some of the most commonly used optional arguments:

BACK  Specifies that a string scan is to be in reverse order (right to left). 
DIM  Specifies a selected dimension of an array argument.  
KIND  Specifies the kind type parameter of the function result. 
MASK  Specifies that a mask can be applied to the elements of the argument array to exclude the elements that are not to be involved in an operation.  

Examples:

The syntax for the DATE_AND_TIME intrinsic subroutine shows four optional positional arguments: DATE, TIME, ZONE, and VALUES. The following shows some valid ways to specify these arguments: 

  ! Keyword example
  CALL DATE_AND_TIME (ZONE=Z)

  ! The following two positional examples are equivalent:
  CALL DATE_AND_TIME (DATE, TIME, ZONE)
  CALL DATE_AND_TIME (, , ZONE)

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