LPARAMETERS
Contents
Purpose
Declare local formal parameters to a procedure or program
Syntax
LPARAMETERS <parameter list>
See Also
&, DECLARE, DO, LOCAL, PARAMETERS, PARAMETERS(), PCOUNT(), PRIVATE, PROCEDURE, PUBLIC, SET LOCAL, SET PROCEDURE
Description
The LPARAMETERS command declares a list of local memory variables or arrays, and assigns them the values of the actual parameters specified on a DO <program | procedure> WITH command. The parameters are initially declared as logicals with the value .F.. The LPARAMETERS command must be the first executable command in a procedure or program. The PCOUNT() function is used to determine how many parameters were passed.
Parameters may be passed which are memory variables (i.e. they are not part of an expression). The contents of these memory variables will be updated when the procedure or program returns. This type of parameter passing is known as call by reference. This is the default for PROCEDURES and PROGRAMS. The '@' character may be placed in front of the memory variable name in User Defined Functions (UDF), so that they are called by reference.
If you do not wish the parameters to be modified by the called PROCEDURE or PROGRAM, you should enclose the memory variable in round brackets. This type of parameter passing is known as call by value. Any expressions that you specify as parameters are always call by value parameters. The default passing of parameters with User Defined Functions (UDF) is call by value. The limit to the number of parameters that you can pass is 40.
The local memory variables created by the LPARAMETERS command are always released when the procedure or program returns.
To declare the parameters as private rather than local, use the PARAMETERS command.
Example
procedure proc2 // proc2 does not have access to the lpara1 and lpara2 parameters declared locally in proc1. //... return procedure proc1 lparameters lpara1, lpara2 proc2() return do proc1 with 10, 40