What is the role of the "THRU" keyword in the "EVALUATE" statement?
- To assign a value to a variable
- To break out of the "EVALUATE" loop
- To indicate the end of the "EVALUATE" block
- To specify a range of conditions
The "THRU" keyword in the "EVALUATE" statement is used to specify a range of conditions. It simplifies code by allowing the same action to be taken for multiple consecutive conditions without listing each one separately.
What are the primary considerations when handling duplicate records in VSAM or ISAM files in COBOL?
- Consolidating duplicate keys into a single record
- Deleting duplicate keys during file creation, using only unique keys
- Ignoring duplicate keys for simplicity, avoiding the use of SORT operations
- Properly handling duplicate keys, utilizing SORT and MERGE operations, ensuring key uniqueness
Handling duplicate records in VSAM or ISAM files involves considerations like properly managing duplicate keys, using sorting operations to organize data, and ensuring key uniqueness to prevent data integrity issues.
What is the primary purpose of using the PERFORM statement in COBOL?
- To define a conditional loop in COBOL
- To execute a set of COBOL statements until a specified condition is met
- To perform arithmetic operations in COBOL
- To repeat a group of COBOL statements a specific number of times
The primary purpose of the PERFORM statement in COBOL is to execute a set of statements until a specified condition (UNTIL) is met, providing a powerful looping mechanism for program control flow.
Which conditional statement in COBOL allows you to test multiple conditions sequentially?
- EVALUATE
- IF-ELSE
- NEXT SENTENCE
- PERFORM UNTIL
The "EVALUATE" statement in COBOL allows you to test multiple conditions sequentially. It provides a concise and structured way to evaluate different conditions and execute corresponding blocks of code based on the true condition.
The USAGE IS _____ clause is used to specify the format of data storage for numeric data types in COBOL.
- COMPUTATIONAL
- DISPLAY
- INDEX
- REDEFINES
In COBOL, the USAGE IS clause is used to define the format of data storage for numeric data types. The COMPUTATIONAL clause, often followed by other keywords like COMP or COMP-3, indicates binary or packed-decimal storage formats.
The PERFORM _______ loop in COBOL allows you to iterate through a range of values.
- TIMES
- UNTIL
- VARYING
- WITH
In a PERFORM loop with the VARYING clause, the loop control variable is incremented or decremented through a specified range of values, allowing iteration through that range. The keyword associated with this functionality is VARYING.
In a COBOL program for processing inventory records, how would you handle exceptions when an item is out of stock and cannot be shipped?
- EXCEPTION/ERROR declarative
- IF statement with GOTO
- PERFORM UNTIL
- READ...INVALID KEY
The EXCEPTION/ERROR declarative in COBOL allows you to handle exceptions, such as an item being out of stock, in a structured manner. It provides a clean separation of error-handling logic from the main processing flow, enhancing code readability and maintainability.
When implementing file locking, the _______ and _______ modes are used to specify the type of access allowed to files.
- Open, Close
- Read, Write
- Sequential, Indexed
- Shared, Exclusive
In COBOL, file locking mechanisms utilize two modes: Shared and Exclusive. Shared mode allows multiple users to read the file simultaneously, while Exclusive mode grants exclusive access to a single user for both reading and writing operations. These modes help control access and prevent conflicts among concurrent users.
In a large-scale COBOL application, you have to manage multiple alternate indexes for an indexed file. What considerations should be taken into account to optimize performance and minimize conflicts?
- Option 1: Use a single alternate index for simplicity
- Option 2: Opt for as many alternate indexes as needed without restrictions
- Option 3: Limit the number of alternate indexes and carefully choose key fields
- Option 4: Choose any fields for alternate indexes to enhance flexibility
Limiting the number of alternate indexes and choosing key fields judiciously is crucial. Each alternate index adds overhead, so selecting only necessary indexes and optimizing key fields ensures better performance and reduces potential conflicts in large-scale applications.
What considerations should be taken into account when using the CONTINUE statement for error handling?
- It can be used to retry the operation that caused the error
- It is reserved for informational messages
- It is used to terminate the program
- It should be avoided for error handling
The CONTINUE statement can be used for error handling by allowing the program to retry the operation that caused the error. Care should be taken to avoid infinite loops and ensure that the error is appropriately handled.