You are working on a mission-critical COBOL application that must continue running even in the presence of non-fatal errors. Which error recovery strategy should you implement to achieve this?
- Graceful degradation
- Process termination
- Use of the PERFORM THRU statement
- Use of the STOP RUN statement
Graceful degradation is an error recovery strategy in COBOL where the application continues to run even in the presence of non-fatal errors. It involves handling errors in a way that allows the program to provide partial functionality while ensuring overall stability.
In COBOL, what is the primary purpose of the INVALID KEY phrase when using the READ verb?
- It indicates the end of the file
- It is a syntax error
- It is used to specify actions to be taken if an I/O operation fails
- It signifies an invalid condition in the data being read
The INVALID KEY phrase in the READ verb is used to handle situations where there is an invalid condition in the data being read. This can include data conversion errors or data integrity issues, allowing the program to take specific actions when such conditions occur.
The COBOL intrinsic function FUNCTION ______ is commonly used for string manipulation.
- LENGTH
- REVERSE
- TRIM
- UPPER-CASE
The FUNCTION TRIM in COBOL is commonly used for string manipulation. It allows you to remove leading and trailing spaces from a string, providing a cleaner and more controlled data representation.
In COBOL, how can you handle multiple conditions efficiently using the "EVALUATE" statement?
- By employing the "ELSE" clause
- By specifying different conditions using "WHEN" clauses
- By using nested "IF" statements
- By utilizing the "ALSO" keyword
The "EVALUATE" statement in COBOL allows efficient handling of multiple conditions by using "WHEN" clauses. Each "WHEN" clause represents a different condition, providing a clear and structured way to handle various cases.
What is the main purpose of error handling in COBOL programs?
- To detect and respond to unexpected situations during program execution
- To enhance program performance
- To improve program readability
- To reduce the size of the program code
Error handling in COBOL is crucial for detecting and responding to unexpected situations, such as invalid input or system errors, ensuring graceful program execution and preventing unintended consequences.
In a team project, you need to create a hierarchy of classes with common attributes and behaviors. How can you implement this efficiently in Object-Oriented COBOL?
- Define a "RECORD" structure
- Implement "SEARCH ALL" operation
- Use the "CLASS" keyword
- Utilize "WORKING-STORAGE" section
To create a hierarchy of classes in Object-Oriented COBOL, you use the "CLASS" keyword. This keyword allows you to define classes with common attributes and behaviors, facilitating the creation of a class hierarchy.
How can you terminate a PERFORM loop in COBOL using the EVALUATE statement?
- By using the BREAK statement
- By using the EXIT PERFORM statement
- By using the WHEN OTHER condition
- By using the WHEN condition with a specific value
The EVALUATE statement in COBOL can be used to terminate a PERFORM loop by incorporating the EXIT PERFORM statement within one of the WHEN conditions. This allows the program to exit the loop based on a specified condition.
Explain the concept of deadlock in the context of file locking in COBOL. How can it be avoided or resolved?
- Deadlock occurs when two or more processes are blocked, each waiting for the other to release a lock. To avoid deadlock, use a consistent order when acquiring locks or implement timeout mechanisms. Resolution involves detecting deadlock and releasing locks in a controlled manner.
- Option 2
- Option 3
- Option 4
Deadlock in COBOL file locking happens when processes are blocked, waiting for each other's locks. Avoiding deadlock involves careful lock acquisition order and implementing timeouts. Resolution includes detecting deadlock and releasing locks systematically.
COBOL provides the _____ clause to specify the data type of elements within a table.
- DATA
- INDEX
- OCCURS
- PIC
COBOL uses the PIC (Picture) clause to specify the data type of elements within a table. It allows you to define the characteristics of the data, such as its format, size, and type.
In indexed file processing, the use of ____________ keys can enhance the performance of record retrieval operations.
- Alternate
- Composite
- Primary
- Secondary
In indexed file processing, secondary keys are additional keys created to enhance the performance of record retrieval operations. These keys provide alternative paths for accessing records, reducing the time and resources required for searching and retrieving specific data.
In the COBOL Procedure Division, which statement is used for making decisions and implementing conditional logic?
- ACCEPT statement
- EVALUATE statement
- IF statement
- PERFORM statement
The EVALUATE statement in COBOL is used for making decisions and implementing conditional logic. It allows for multiple conditions to be tested, and corresponding actions to be taken based on the true condition.
What is the purpose of the INITIALIZE verb in COBOL?
- To declare variables in COBOL
- To initialize variables with random values
- To set all data items to their default values
- To terminate the COBOL program
The INITIALIZE verb in COBOL is used to set all data items to their default values. It is commonly used at the beginning of a program to initialize variables and data structures before processing begins.