Assignment (=) statement

Assigns the value of an expression to a database field or variable.

Data movement



Syntax

field = expression [ NO-ERROR ]
field
The name of an ABL data element to which you want to assign the value of expression and that is defined with a data type that is compatible with the data type of expression. This data element can include a:
  • Database or temp-table field
  • Variable scoped to the current procedure, user-defined function, or method of a class or an accessible class-based variable data member, including a subscripted or unsubscripted array variable
  • Parameter defined for the current procedure, user-defined function, or method of a class, including a subscripted or unsubscripted array parameter
  • Writable class-based or COM property, including a subscripted or unsubscripted array property
  • Writable handle attribute (such as PRIVATE-DATA)
  • Writable system handle (such as CURRENT-WINDOW)
  • ABL syntax that specifies a keyword-driven assignment statement (such as the PROPATH statement, SUBSTRING statement, or similar statement)
expression
An expression with a data type that is consistent with the data type of field. For more information, see the Expression reference entry.
NO-ERROR
Suppresses ABL errors or error messages that would otherwise occur and diverts them to the ERROR-STATUS system handle. If an error occurs, the action of the statement is not done and execution continues with the next statement. If the statement fails, any persistent side-effects of the statement are backed out. If the statement includes an expression that contains other executable elements, like methods, the work performed by these elements may or may not be done, depending on the order the AVM resolves the expression elements and the occurrence of the error.

For the Assignment (=) statement with NO-ERROR, if ERROR is raised, then the leftside of the assignment will be unchanged.

To check for errors after a statement that uses the NO-ERROR option:

  • Check the ERROR-STATUS:ERROR attribute to see if the AVM raised the ERROR condition.
  • Check if the ERROR-STATUS:NUM-MESSAGES attribute is greater than zero to see if the AVM generated error messages. ABL handle methods used in a block without a CATCH end block treat errors as warnings and do not raise ERROR, do not set the ERROR-STATUS:ERROR attribute, but do add messages to the ERROR-STATUS system handle. Therefore, this test is the better test for code using handle methods without CATCH end blocks. ABL handle methods used in a block with a CATCH end block raise ERROR and add messages to the error object generated by the AVM. In this case, the AVM does not update the ERROR-STATUS system handle.
  • Use ERROR-STATUS:GET-MESSAGE( message-num ) to retrieve a particular message, where message-num is 1 for the first message.

If the statement does not include the NO-ERROR option, you can use a CATCH end block to handle errors raised by the statement.

Some other important usage notes on the NO-ERROR option:

  • NO-ERROR does not suppress errors that raise the STOP or QUIT condition.
  • A CATCH statement, which introduces a CATCH end block, is analogous to a NO-ERROR option in that it also suppresses errors, but it does so for an entire block of code. It is different in that the error messages are contained in a class-based error object (generated by the AVM or explicitly thrown), as opposed to the ERROR-STATUS system handle. Also, if errors raised in the block are not handled by a compatible CATCH block, ON ERROR phrase, or UNDO statement, then the error is not suppressed, but handled with the default error processing for that block type.
  • When a statement contains the NO-ERROR option and resides in a block with a CATCH end block, the NO-ERROR option takes precedence over the CATCH block. That is, an error raised on the statement with the NO-ERROR option will not be handled by a compatible CATCH end block. The error is redirected to the ERROR-STATUS system handle as normal.
  • If an error object is thrown to a statement that includes the NO-ERROR option, then the information and messages in the error object will be used to set the ERROR-STATUS system handle. This interoperability feature is important for those integrating code that uses the traditional NO-ERROR technique with the newer, structured error handling that features error objects and CATCH end blocks.

Example

This procedure resets all the monthly quota values to 2500 in all salesrep records. If you want to set values for individual array elements, you can do so by making an explicit assignment using the assignment statement and a specific array reference, such as month-quota[1] or month-quota[i].

r-asgmnt.p

DEFINE VARIABLE ctr AS INTEGER NO-UNDO.

FOR EACH SalesRep:
  DO ctr = 1 TO 12:
    SalesRep.MonthQuota[ctr] = 2500.
  END.
END.

Notes

See also

ASSIGN statement, CAST function, Class-based object reference, COPY-DATASET( ) method, COPY-LOB statement, COPY-TEMP-TABLE( ) method, Data types, Expression, FIX-CODEPAGE statement, NEW statement