In the "ENVIRONMENT DIVISION," the "INPUT-OUTPUT SECTION" defines the _____ used by the program.
- Data manipulation rules
- External data files and devices
- Procedure names
- Program documentation
In the "ENVIRONMENT DIVISION" of COBOL, the "INPUT-OUTPUT SECTION" is responsible for defining the external data files and devices used by the program. This section specifies the properties and characteristics of input and output operations.
COBOL programs can optimize file handling performance by utilizing ____________ to store frequently accessed records in memory.
- Buffering
- Hashing
- Indexing
- Sorting
Buffering is a technique in COBOL where frequently accessed records are stored in memory buffers, reducing the need for frequent disk I/O operations and improving overall file handling performance. It helps in minimizing the time required to read or write records from/to external files.
Why might you choose variable-length records over fixed-length records in COBOL file processing?
- To enforce strict record size consistency
- To improve processing speed in sequential file access
- To save storage space by avoiding padding unused portions
- To simplify program logic and enhance readability
Choosing variable-length records in COBOL can save storage space by avoiding the need to pad unused portions. It is especially beneficial when dealing with data of varying lengths, reducing wasted storage.
In COBOL, what happens when you declare a variable in the DATA DIVISION but outside of any specific procedure?
- The variable becomes global and can be accessed by all procedures within the program
- The variable is accessible only within the procedure where it is declared
- The variable is deallocated after each procedure call
- The variable is initialized automatically
When a variable is declared in the DATA DIVISION outside of any specific procedure, it becomes global in scope. This means it can be accessed by all procedures within the program, making it available throughout the program's execution.
How does COBOL handle multi-user access to VSAM and ISAM files, and what are the potential issues?
- COBOL doesn't support multi-user access to VSAM and ISAM files
- COBOL ensures exclusive file access for each user to prevent conflicts
- COBOL relies on external tools for multi-user file access
- COBOL utilizes file locking mechanisms to allow multiple users simultaneous access
COBOL handles multi-user access to VSAM and ISAM files through file locking mechanisms. Potential issues include contention for locks, leading to delays, and the need for careful coordination to avoid conflicts and data inconsistencies.
What does the CLOSE verb with the REEL and UNIT clauses signify when used in COBOL file handling?
- It closes a file and releases resources, specifying the reel and unit information
- It indicates the end of the file
- It is not a valid combination for the CLOSE verb
- It is used to close a magnetic tape file
The CLOSE verb with the REEL and UNIT clauses in COBOL is used to close a file and release associated resources, specifying the reel and unit information for files like magnetic tapes. It ensures proper termination of file processing.
In COBOL, the _______ clause is used to declare exception conditions that can be raised during program execution.
- ERROR
- EXCEPTION
- INVALID
- ON EXCEPTION
In COBOL, the EXCEPTION clause is used to declare exception conditions. It allows the programmer to specify the actions to be taken when an exceptional situation occurs during program execution.
The _____ verb in COBOL is used for assigning values to data items.
- COMPUTE
- INITIALIZE
- MOVE
- SET
In COBOL, the MOVE verb is used for assigning values to data items. It allows you to transfer data from one data item to another.
In COBOL, the "Extend" access mode is used for _____
- Adding new records to a file
- Deleting records from a file
- Modifying existing records
- Reading records sequentially
The "Extend" access mode in COBOL is used for adding new records to a file. When opening a file in "Extend" mode, the file position indicator is set to the end of the file, allowing new records to be appended.
The "WHEN OTHER" condition in the "EVALUATE" statement is similar to the "OTHERWISE" clause in a _____ statement.
- CASE
- IF
- PERFORM
- SELECT
The "WHEN OTHER" condition in the "EVALUATE" statement functions similarly to the "OTHERWISE" clause in a "CASE" statement. It captures any conditions not explicitly specified in preceding "WHEN" clauses, providing a default action.
What is the difference between a procedure and a function in COBOL?
- A procedure can only be called within the same program, while a function can be used across programs
- A procedure cannot have parameters, while a function can have parameters
- A procedure does not return a value, while a function returns a value
- A procedure is defined using the PROCEDURE DIVISION, while a function is defined in the DATA DIVISION
In COBOL, a procedure is a set of statements that perform a specific task but does not return a value. On the other hand, a function is a subprogram that returns a value to the calling program. Understanding this distinction is crucial for designing modular and reusable code.
When working with indexed files, the _____ clause is used to specify the key structure.
- INDEXED
- KEYS
- OCCURS
- SORT
The KEYS clause in COBOL is used when working with indexed files to specify the key structure. It defines the fields that make up the index key, facilitating efficient access to records in the indexed file.