COBOL, what is "ON EXCEPTION UNDO" used for in error handling?
- To display an error message to the user
- To ignore exceptions and proceed with the program execution
- To roll back changes made to the file in case of an exception
- To terminate the program when an exception occurs
"ON EXCEPTION UNDO" in COBOL is used to roll back changes made to the file in case of an exception. It ensures data consistency by undoing any modifications made before the exception occurred.
In a COBOL program, when using a PERFORM loop with the VARYING clause, what is the role of the INDEX variable?
- It is not applicable to PERFORM loops with the VARYING clause
- It is used to control the loop execution by specifying the increment value
- It represents the total number of iterations in the loop
- It serves as a loop counter, indicating the current iteration
The INDEX variable in a PERFORM loop with the VARYING clause is crucial as it acts as a loop counter, keeping track of the current iteration. Program logic can be based on the value of the INDEX variable within the loop.
What does VSAM stand for in the context of COBOL file handling?
- Variable Storage Allocation Method
- Very Sequential Access Method
- Virtual Storage Access Method
- Volatile Storage Access Module
VSAM stands for Virtual Storage Access Method in the context of COBOL file handling. It is a file storage access method used to organize records in a file in a way that allows direct access to data based on the key.
Your COBOL program needs to maintain a counter that keeps track of the number of times a specific operation is performed. Which type of variable is suitable for this task?
- PIC 9(3) USAGE DISPLAY
- PIC 9(4)
- PIC 9(5) USAGE COMP-3
- PIC S9(6) USAGE COMP
For maintaining a counter in COBOL, PIC S9(6) USAGE COMP is appropriate. It is a signed numeric type that efficiently stores and increments numeric values.
How are COBOL group data items different from elementary data items?
- Group data items are always numeric, whereas elementary data items can be alphanumeric
- Group data items can contain other data items, including other groups, while elementary data items cannot
- Group data items cannot have a picture clause, unlike elementary data items
- Group data items do not support the REDEFINES clause, unlike elementary data items
COBOL group data items differ from elementary data items in that they can contain other data items, including other groups. This hierarchical structure allows for better organization and abstraction in the data design of a COBOL program.
Can you use the REDEFINES clause to redefine a group data item in COBOL?
- No, REDEFINES can only be applied to elementary items
- No, group data items cannot be redefined in COBOL
- Yes, but only if the group data item has a subordinate item
- Yes, it allows a group data item to be redefined by another group or elementary item
In COBOL, the REDEFINES clause can be used to redefine a group data item. It allows a group data item to share the same storage space with another group or elementary item, providing flexibility in data structure representation.
The "AT END" clause is often used in conjunction with the "NOT ON EXCEPTION" clause to handle errors that occur at the _____ of file processing.
- Beginning
- End
- Middle
- Start
The "AT END" clause in COBOL is used in conjunction with the "NOT ON EXCEPTION" clause to handle errors that occur at the end of file processing. This is useful for performing cleanup or finalization tasks before the program concludes.
The PERFORM _______ loop in COBOL allows you to iterate through a range of values.
- TIMES
- UNTIL
- VARYING
- WITH
In a PERFORM loop with the VARYING clause, the loop control variable is incremented or decremented through a specified range of values, allowing iteration through that range. The keyword associated with this functionality is VARYING.
When using a PERFORM loop with the VARYING clause, the _______ clause defines the initial and final values for the loop control variable.
- BY
- FROM
- THRU
- TO
The VARYING clause in a COBOL PERFORM loop is used along with the FROM and TO keywords to specify the initial and final values for the loop control variable, determining the range of iteration.
When handling exceptions in COBOL programs, the "HANDLE EXCEPTION" phrase allows you to define custom _____ routines.
- Error reporting
- Exception handling
- Logging
- Recovery
The "HANDLE EXCEPTION" phrase in COBOL enables the programmer to define custom recovery routines that specify the actions to be taken when a specific exception is encountered. This facilitates customized exception handling and program recovery strategies.