The "EVALUATE" statement can be used to simulate a _____ statement with multiple conditions.
- DIVIDE
- GOTO
- PERFORM
- Switch
The "EVALUATE" statement in COBOL serves a similar purpose as a "switch" statement in other programming languages. It allows for multiple conditions to be tested, providing a structured and efficient way to handle different cases.
In COBOL, what is the difference between the ADD and SUBTRACT statements when performing arithmetic operations?
- ADD adds values, and SUBTRACT subtracts values from the receiving field
- ADD and SUBTRACT are interchangeable in COBOL
- ADD is used for numeric addition, and SUBTRACT is used for alphanumeric subtraction
- ADD is used for subtraction, and SUBTRACT is used for addition
The ADD statement in COBOL is used for numeric addition, while the SUBTRACT statement is used for numeric subtraction. It's crucial to understand the distinction to perform accurate arithmetic operations in COBOL programs.
You are working on a COBOL program that performs a merge operation on two sorted files. How can you ensure that the merge operation is efficient and optimized for performance?
- Implementing a binary search algorithm
- Pre-sorting the input files before merging
- Using indexed files for both input files
- Using the SORT verb provided by COBOL
Pre-sorting the input files before merging ensures that the records are already in sorted order, which simplifies the merge process and improves performance. This reduces the need for complex sorting algorithms during the merge operation.
What is parameter passing in subprograms, and why is it important?
- Parameter passing is a mechanism to pass data between programs and is important for sharing information
- Parameter passing is not supported in COBOL
- Parameter passing is only applicable to procedures, not functions
- Parameter passing refers to the allocation of storage for variables in a subprogram
Parameter passing in subprograms involves transferring data between the calling program and the called subprogram. It allows the subprogram to receive input values, process them, and potentially return results to the calling program. This mechanism enhances code modularity and facilitates code reuse.
In a COBOL "IF" statement, what happens if the condition is not met?
- An error is generated
- The "ELSE" statement is executed
- The control transfers to the next statement outside the "IF" block
- The program terminates abruptly
If the condition in a COBOL "IF" statement is not met, the control transfers to the next statement outside the "IF" block. If an "ELSE" statement is present, it will be executed; otherwise, the program continues with the next statement.
In COBOL, the _______ statement is used to perform a series of statements repeatedly.
- ITERATE
- LOOP
- PERFORM
- REPEAT
The PERFORM statement in COBOL is used to create loops, allowing a series of statements to be executed repeatedly. It provides various clauses for controlling the loop, such as UNTIL, WITH TEST BEFORE, and WITH TEST AFTER.
In the context of COBOL file handling, what is "read-ahead" and how does it contribute to performance improvement?
- It reads multiple records in advance to reduce I/O wait time
- It reads records from the end of the file first
- It reads records sequentially for faster processing
- It skips unnecessary records during reading
"Read-ahead" in COBOL involves reading multiple records in advance and buffering them in memory, reducing I/O wait time and enhancing performance by minimizing the need for repeated disk access.
In a COBOL program, what is the primary use of the VARYING clause within a PERFORM loop?
- To control the flow of execution in nested loops
- To define variables with varying data types
- To execute the loop only if a condition is met
- To iterate over a range of values for a loop variable
The VARYING clause in a PERFORM loop is used to iterate over a range of values for a loop variable, allowing the repeated execution of a block of code with different values during each iteration.
In COBOL, what is the purpose of the ACCESS MODE clause when working with relative files?
- DYNAMIC
- KEY
- RANDOM
- SEQUENTIAL
The ACCESS MODE clause in COBOL specifies how records in a relative file are accessed. RANDOM allows direct access to records based on the record number. This is useful when individual records need to be retrieved without the need to read sequentially through the file.
When working with COBOL structures, the POINTER clause is used to indicate the ___________ of the current element within the structure.
- Address
- Index
- Position
- Size
In COBOL, the POINTER clause is used to indicate the memory address of the current element within the structure. It allows for dynamic memory manipulation and is often used in conjunction with the USAGE IS POINTER clause.