In COBOL, what does the "INVALID KEY" phrase do in the context of file processing?
- It denotes the key attribute for a record in a file
- It indicates that the file is corrupted and cannot be used
- It is used to declare a key as invalid in the file definition
- It is used to specify the action to be taken when an invalid key is encountered during file processing
The "INVALID KEY" phrase in COBOL is used to specify the action to be taken when an invalid key is encountered during file processing. This allows the program to handle errors gracefully and take appropriate actions, such as providing a default value or performing specific error-handling logic.
In COBOL, can you have a table with varying numbers of occurrences for each element?
- No, COBOL tables can only have a fixed number of occurrences
- No, COBOL tables must have a fixed number of occurrences for each element
- Yes, COBOL allows tables with varying numbers of occurrences for each element
- Yes, but it requires advanced programming techniques
Yes, in COBOL, tables can have varying numbers of occurrences for each element. This flexibility allows for more dynamic data structures in programs.
When working with variable-length records in COBOL, what additional information is often stored along with the data?
- Record Identifier
- Record Length
- Record Padding
- Record Type
When dealing with variable-length records in COBOL, the additional information often stored along with the data is the "Record Length." This length information helps the program know the size of each record in the file.
What is the significance of the OCCURS clause when used with group data items?
- It controls the iteration of a loop in a COBOL program
- It defines the level of the group item
- It defines the number of occurrences of a group item in an array
- It specifies the occurrence of a particular value within the group
The OCCURS clause in COBOL is used to define the number of occurrences of a group item, creating an array. It allows you to work with repeating data structures efficiently.
What is the main objective of file handling performance optimization in COBOL?
- Increase program complexity
- Maximize file size
- Minimize I/O operations
- Optimize CPU usage
The primary objective of file handling performance optimization in COBOL is to minimize I/O operations. This involves reducing the number of reads and writes to files, which enhances overall program efficiency and execution speed.
Which arithmetic operator is used to perform subtraction in COBOL?
- * (Multiply)
- + (Plus)
- - (Minus)
- / (Divide)
The subtraction operation in COBOL is represented by the minus (-) operator. It is used to subtract one numeric value from another in COBOL programs.
In COBOL, the REDEFINES clause is often used to share memory space between two data items with different _____
- Data Types
- Lengths
- Names
- Values
The REDEFINES clause in COBOL allows two or more data items to share the same memory space, but it's crucial that the redefined data items have the same starting lengths to avoid conflicts in memory allocation.
Your COBOL program interacts with external devices, and you want to handle errors gracefully without abruptly ending the program. Which statement is suitable for this scenario?
- CONTINUE
- EXIT PROGRAM
- HANDLE EXCEPTION
- STOP RUN
In this scenario, the CONTINUE statement is appropriate for handling errors gracefully without abruptly ending the COBOL program. It allows the program to proceed with the next statement, facilitating controlled error handling.
You are developing a COBOL program that reads data from an existing file and updates specific records. Which file access mode should you choose for this operation?
- EXTEND
- I-O
- INPUT
- OUTPUT
In this scenario, the correct file access mode is I-O (Input-Output). This mode allows both reading and updating of records in an existing file. It is suitable for situations where data needs to be read and modified within the same program.
When should you use the "Output" file access mode in COBOL?
- To perform both read and write operations on the file
- To read records sequentially from the file
- To update records in the file
- To write records to the file
The "Output" file access mode in COBOL is used when you want to write records to the file. It allows the program to add new records to the file but does not allow reading or updating of existing records.