You are working on a COBOL program to store and manipulate a list of customer IDs. Which data structure would you choose between an array and a table, and why?
- Array
- Both Array and Table
- Neither Array nor Table
- Table
In this scenario, a table in COBOL would be more suitable. A table allows dynamic allocation of storage based on the actual number of customer IDs, providing flexibility in managing varying amounts of data efficiently. Arrays have a fixed size, which may lead to inefficient memory usage.
When should you use record-level locking as opposed to file-level locking in a COBOL application?
- When multiple users need to access different records within the same file concurrently
- When only one user is expected to access the file at a time
- When the file is read-only and no updates are required
- When the file is small and doesn't require any locking
Record-level locking in COBOL is preferred when multiple users need to access different records within the same file concurrently. This approach allows for more granular control over the locking mechanism, reducing contention and improving system efficiency.
What is the key difference between VSAM and ISAM file organizations in COBOL?
- ISAM provides better performance than VSAM
- VSAM allows for direct access to records based on a key, while ISAM supports sequential access only
- VSAM and ISAM both use the same file organization
- VSAM is only used for read operations, while ISAM is used for both read and write operations
The key difference between VSAM and ISAM is that VSAM allows for direct access to records based on a key, enabling quick retrieval of specific records, while ISAM supports sequential access only, requiring the records to be read in order.
In a COBOL "IF" statement, the "NEXT SENTENCE" phrase is used to _____
- Provide comments within the "IF" block
- Specify the condition for the "IF" statement
- Transfer control to the next executable sentence following the "IF" statement
- Trigger an error condition
The "NEXT SENTENCE" phrase in a COBOL "IF" statement transfers control to the next executable sentence following the "IF" block, skipping the subsequent sentences if the condition is true.
What is the purpose of using records and structures in COBOL?
- To define individual data items
- To enhance program logic
- To group related data items together
- To optimize program execution
Records and structures in COBOL are used to group related data items together. This allows for better organization of data and improves code readability by representing entities as a single unit.
_____ is a mechanism in Object-Oriented COBOL that allows a class to inherit properties and behaviors from another class.
- DERIVE
- EXTEND
- INCLUDE
- INHERIT
In Object-Oriented COBOL, the "DERIVE" keyword is used as a mechanism to allow a class to inherit properties and behaviors from another class, promoting code reusability.
In a COBOL project, you have a common calculation that is used in multiple programs. How can you efficiently reuse this calculation using subprograms?
- Copybooks
- Inline Code
- Macro Expansion
- Subprograms (Perform)
By encapsulating the common calculation in a subprogram using the PERFORM statement, you can efficiently reuse the logic across multiple programs, promoting code reusability and maintainability.
You are designing a COBOL program to process customer names, which may include special characters. Which data type should you use to accommodate these special characters?
- PIC A(n)
- PIC N(n)
- PIC S9(n)
- PIC X(n)
The PIC X(n) data type in COBOL is suitable for processing customer names that may include special characters. It is a generic alphanumeric data type, accommodating a variety of characters without imposing specific constraints on the input.
You are debugging a complex COBOL program, and you encounter a "segmentation fault." What does this error indicate, and what debugging steps would you take to address it?
- Compilation error
- Logic error
- Memory access violation
- Syntax error
A segmentation fault in COBOL typically indicates a memory access violation, often caused by attempting to access memory that the program doesn't have permission to access. To address this issue, debugging steps may include analyzing the program's memory usage, checking for array out-of-bounds accesses, inspecting pointer usage, and using tools like memory debuggers or runtime analysis tools to identify the source of the error.
When dealing with a sequential file, which file organization is commonly used for reading records in a specified order?
- Dynamic
- Indexed
- Relative
- Sequential
In a sequential file organization, records are stored and retrieved in a specific order. This order is determined by the physical sequence in which the records are written to the file. This organization is suitable for scenarios where records need to be processed in a predetermined order.