Description
Moves the contents of one variable into another variable, and clears the original variable.
Syntax
Transfer variable1 To variable2
Parameters
The Transfer statement accepts arguments for the following parameters.
| Parameter | Description |
|---|---|
| variable1 | The source variable. After the execution of a Transfer statement, variable1 is null. |
| variable2 | The target. After a transfer, variable2 contains the data originally represented by variable1. It is not necessary to initialize the target variable before transferring to it. |
Remarks
The Transfer statement moves the value of a variable by reference. Instead of copying the data represented by a variable, Transfer copies the pointer to that data. The effect is a very quick reassignment, with no loss of memory.
If the contents of a variable are copied using an assignment operator (for example, A = B), BASIC+ makes a copy of the value in the source variable (B), and loads it into the location represented by the target variable (A). The assignment operator is a transfer by value. This consumes both time and memory, and thus direct assignment is less efficient than using the Transfer statement.
Example
/* The program processes each record in the CUSTOMER file. After calling the external program RECORD_STATS, the program restores the values of @RECORD and @ID by transferring them from temporary variables. The local subroutine FURTHER_PROCESSING is not shown. */ Open "TEST" To CUSTOMER_TABLE Else status = Set_FSError() Return End Select CUSTOMER_TABLE Done = 0 Loop ReadNext @ID Else Done = 1 Until Done Read @RECORD From CUSTOMER_TABLE, @ID Then * save contents before calling routine * in case RECORD_STATS changes values SAVE_RECORD = @RECORD SAVE_ID = @ID Call RECORD_STATS * restore contents Transfer SAVE_RECORD To @RECORD Transfer SAVE_ID To @ID GoSub Further_Processing End Repeat
