hb_PIsByRef()

Determine if a parameter is passed by reference.

Syntax

      hb_PIsByRef( nParam ) --> <lParamIsByRef>

Arguments

<nParam> is the parameter number to test.

Returns

<lVarIsByRef> a logical value indicating if the parameter is passed by reference to actual function or procedure.

Description

This function return a logical value indicating if the parameter is passed by reference to actual function or procedure.

This function is based on the form that Harbour manages to the variables for reference. When a variable is passed by reference, what receives the function or procedure is, a pointer to the previous variable, be this the container variable of the data or a pointer to another variable. The function observes if the variable passed points to a common variable or to a variable passed by reference.

Examples

      PROCEDURE Main()
         LOCAL cVar := "Test local"
         MEMVAR m_nVar
         PRIVATE m_nVar := 0

         Test( @cVar, @m_nVar, cVar, m_nVar )
         RETURN

      STATIC PROCEDURE Test( Arg1, Arg2, Arg3, Arg4 )
         ? hb_PIsByRef( 1 )        // .T.
         ? hb_PIsByRef( 2 )        // .T.
         ? hb_PIsByRef( 3 )        // .F.
         ? hb_PIsByRef( 4 )        // .F.
         RETURN

Compliance

Harbour

Files

Library is core

Seealso

ValType()

FieldBlock	Return a code block that sets/gets a value for a given field
FieldWBlock	Return a sets/gets code block for field in a given work area
HB_AParams	Returns an array containing values of all parameters passed to a function, method or procedure
HB_ArgC	Returns the number of command line arguments
HB_ArgCheck	Checks existence of an internal switch on the command line
HB_ArgShift	Updates HB_Arg* parameter list removing the 1-st one and replacing it by others
HB_ArgString	Retrieves the vale of an internal switch set on the command line.
HB_ArgV	Retrieves the value of a command line argument
HB_PIsByRef	Determine if a parameter is passed by reference.
HB_PValue	Retrieves the value of an argument.
HB_ValToStr	Converts any scalar type to a string.
MemVarBlock	Returns a codeblock that sets/gets a value of memvar variable
PCount	Retrieves the number of arguments passed to a function.
Type	Retrieves the type of an expression
ValType	Retrieves the data type of an expression

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Tag Archives: hb_PIsByRef()

Harbour All Functions – H

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hb_PIsByRef()

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