C5_PARAMETERS

PARAMETERS
 Create private parameter variables
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 Syntax

     PARAMETERS <idPrivate list>

 Arguments

     <idPrivate list> is one or more parameter variables separated by
     commas.  The number of receiving variables does not have to match the
     number of arguments passed by the calling procedure or user-defined
     function.

 Description

     The PARAMETERS statement creates private variables to receive passed
     values or references.  Receiving variables are referred to as
     parameters.  The values or references actually passed by a procedure or
     user-defined function invocation are referred to as arguments.

     When a PARAMETERS statement executes, all variables in the parameter
     list are created as private variables and all public or private
     variables with the same names are hidden until the current procedure or
     user-defined function terminates.  A PARAMETERS statement is an
     executable statement and, therefore, can occur anywhere in a procedure
     or user-defined function, but must follow all compile-time variable
     declarations, such as FIELD, LOCAL, MEMVAR, and STATIC.

     Parameters can also be declared as local variables if specified as a
     part of the PROCEDURE or FUNCTION declaration statement (see the
     example).  Parameters specified in this way are referred to as formal
     parameters.  Note that you cannot specify both formal parameters and a
     PARAMETERS statement with a procedure or user-defined function
     definition.  Attempting to do this results in a fatal compiler error and
     an object file is not generated.

     In Clipper the number of arguments and parameters do not have to
     match.  If you specify more arguments than parameters, the extra
     arguments are ignored.  If you specify fewer arguments than parameters,
     the extra parameters are created with a NIL value.  If you skip an
     argument, the corresponding parameter is initialized to NIL.  The
     PCOUNT() function returns the position of the last argument passed in
     the list of arguments.  This is different from the number of parameters
     passed since it includes skipped parameters.

     For more information on passing parameters, refer to the Functions and
     Procedures section in the "Basic Concepts" chapter of the Programming
     and Utilities Guide.

 Examples

     .  This user-defined function receives values passed into private
        parameters with a PARAMETERS statement:

        FUNCTION MyFunc
           PARAMETERS cOne, cTwo, cThree
           ? cOne, cTwo, cThree
           RETURN NIL

     .  This example is similar, but receives values passed into local
        variables by declaring the parameter variables within the FUNCTION
        declaration:

        FUNCTION MyFunc( cOne, cTwo, cThree )
           ? cOne, cTwo, cThree
           RETURN NIL

See Also: FUNCTION LOCAL PCOUNT() PRIVATE PROCEDURE STATIC

 

5 responses to “C5_PARAMETERS

  1. Pingback: Variable Handling | Viva Clipper !

  2. Pingback: C5 Flow Control | Viva Clipper !

  3. Pingback: C5 Statements | Viva Clipper !

  4. Pingback: C5_STATIC | Viva Clipper !

  5. Pingback: C5_PROCEDURE | Viva Clipper !

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