Which COBOL file access mode is commonly used with VSAM and ISAM files when data can be both read and written?
- EXTEND
- I-O (Input-Output)
- INPUT
- OUTPUT
The I-O (Input-Output) file access mode is commonly used with VSAM and ISAM files when data can be both read and written. This mode allows for a combination of read and write operations on the file.
In COBOL, which file organization is most suitable for direct access to records by a specific key?
- Dynamic
- Indexed
- Relative
- Sequential
Indexed file organization in COBOL is most suitable for direct access to records by a specific key. It allows for efficient retrieval based on a defined key value, enabling faster data access compared to sequential or relative file organizations.
What are variable-length records in COBOL primarily used for?
- Efficiently storing records of fixed length
- Facilitating random access to records
- Handling varying-length data, like free-form text
- Simplifying program logic
Variable-length records in COBOL are primarily used for handling data with varying lengths, such as free-form text or variable-length fields. This flexibility allows for efficient storage of data with dynamic lengths.
You are working on a COBOL application that handles variable-length records in an employee database. Each record contains a variable number of dependents. How would you dynamically calculate the length of each record based on the number of dependents?
- DEPENDING ON
- LINAGE IS 66
- OCCURS
- RECORDING MODE IS V
The DEPENDING ON clause in COBOL is used to dynamically calculate the length of a record based on the value specified in another field. In this case, the number of dependents would determine the length of each record, allowing for flexibility in handling variable-length data.
When using the READ verb in COBOL, what happens when the end-of-file (EOF) condition is encountered?
- The program ignores the EOF condition
- The program terminates abruptly
- The system automatically opens the next available file
- The system raises an end-of-file (EOF) status code
When the READ verb in COBOL encounters the end-of-file (EOF) condition, the system raises an end-of-file status code. This allows the program to handle the conclusion of file processing gracefully.
How do you perform date arithmetic in COBOL, such as adding or subtracting days from a date?
- COBOL does not support date arithmetic
- Use the ADD and SUBTRACT statements
- Use the intrinsic function DATE-OF-INTEGER
- Utilize the COMPUTE statement
In COBOL, you perform date arithmetic, such as adding or subtracting days from a date, by using the ADD and SUBTRACT statements. These statements allow you to manipulate date fields with ease.
When working with indexed files, the ______ clause is used to define the structure of the index file.
- INDEX
- KEY
- ORGANIZATION
- RECORD
In COBOL, the ORGANIZATION clause is used to define the structure of the index file when working with indexed files. It specifies whether the file is sequential or indexed and sets the rules for accessing data efficiently.
When working with arithmetic operations in COBOL, the ________ statement is used to control the flow of execution based on conditions.
- ADD
- EVALUATE
- MOVE
- PERFORM
The EVALUATE statement in COBOL is used for conditional execution based on the result of arithmetic operations. It allows for a concise and readable way to handle multiple conditions.
When using a relative file organization, the _____ number is used to access records.
- File
- Index
- Record
- Relative
In a relative file organization in COBOL, the relative record number is used to access records. This number specifies the position of the record relative to the beginning of the file, allowing for direct access to specific records.
You are developing a COBOL program that reads data from an external file. What would you do if the file does not exist when you attempt to open it?
- Check the FILE STATUS after the OPEN statement
- Perform a manual check using IF conditions
- Use the INVALID KEY clause in the file control entry
- Utilize the EXIT PROGRAM statement
When attempting to open a file, using the INVALID KEY clause in the file control entry allows you to handle the situation where the file does not exist. You can specify a set of actions to be taken if the file opening fails, providing a mechanism for graceful error handling.