Your project involves designing a system where multiple classes need to adhere to a specific contract and implement certain methods. Which Object-Oriented COBOL feature would be most suitable for this scenario?
- Abstract Classes
- Interfaces
- Multiple Inheritance
- Overloading
In Object-Oriented COBOL, Interfaces are used to define a contract that multiple classes must adhere to by implementing specific methods. This promotes consistency and standardization across classes in a system.
When using the "USE AFTER EXCEPTION" phrase with the READ statement in COBOL, what happens if the exception condition is not encountered?
- The READ statement will be ignored
- The file will be closed automatically
- The next statement after the READ is executed
- The program will terminate with an error
If the exception condition specified by "USE AFTER EXCEPTION" is not encountered during the READ statement execution, the control will pass to the next statement after the READ. It allows the program to continue execution without interruption.
Explain how COBOL handles file locking and multi-user access when using the "I-O" mode.
- COBOL doesn't support file locking
- COBOL implements record-level locking to ensure data integrity
- COBOL restricts access to one user at a time
- COBOL utilizes system-level file locking mechanisms to prevent conflicts
When using the "I-O" mode in COBOL, file locking and multi-user access are typically handled by system-level mechanisms rather than by COBOL itself. COBOL programs can utilize features provided by the operating system to implement file locking and ensure data integrity in multi-user environments.
In a COBOL program, if you have a numeric data item defined as USAGE COMP-3, what is the effect of applying the REDEFINES clause to it?
- It allows the same data to be referenced using different data descriptions
- It converts the COMP-3 data to COMP data
- It defines a new data item with the same name
- It is not allowed to use REDEFINES with COMP-3
The REDEFINES clause in COBOL allows the same storage space to be referenced using different data descriptions. When applied to a numeric data item with USAGE COMP-3, it enables sharing the same memory location with other data items, potentially of different types.
What is the result of dividing an integer by zero in COBOL?
- Arithmetic Exception
- Compiler Error
- Infinity
- Zero
Dividing an integer by zero in COBOL results in an arithmetic exception. The program will encounter a runtime error due to division by zero, and appropriate error handling should be implemented to address such scenarios.
Explain the significance of the SHAREOPTION clause when dealing with VSAM indexed files in a multi-user environment.
- ALLOWREAD
- DENYNONE
- DENYREAD
- DENYWRITE
The SHAREOPTION clause in COBOL is crucial when dealing with VSAM indexed files in a multi-user environment. It specifies the level of file sharing allowed among users. DENYWRITE, for example, prevents other users from writing to the file simultaneously, ensuring data integrity.
How is a national (Unicode) character data type defined in COBOL?
- COBOL does not support Unicode
- PIC N
- PIC U(10)
- PIC X(10) UNICODE
In COBOL, a national (Unicode) character data type is defined using the PIC N clause. This allows the representation of Unicode characters in the program, ensuring compatibility with international character sets.
The _____ data type in COBOL is used for handling variable-length records in files.
- INDEX
- OCCURS
- REDEFINES
- VARYING
The VARYING clause in COBOL is used for handling variable-length records in files. It allows a field to have a variable length based on the actual data stored. This is particularly useful when dealing with records of varying sizes in file processing.
You are designing a COBOL program for inventory management, and you need to keep track of each item's stock levels. Explain how you would employ the OCCURS clause with the DEPENDING ON phrase in this scenario.
- Depending On
- Grouping
- Indexing
- Non-indexed
In inventory management, using the OCCURS clause with the DEPENDING ON phrase is suitable. It allows dynamic allocation of storage based on the value of a data item, enabling flexibility in handling varying stock levels for different items.
What are duplicate records in the context of COBOL file handling?
- Records containing errors
- Records marked for deletion
- Records with identical key values in a file
- Records with the same data but different key values
Duplicate records in COBOL file handling refer to those with identical key values. These records are distinguished based on a specified key field, and the duplicates must be managed to avoid data inconsistencies.