COBOL Programming Fundamentals

BLANK WHEN ZERO clause has specific restrictions in COBOL. Level 66 is RENAMES (renaming clause), level 88 is condition names (not actual data fields), and signed fields have special storage requirements that don't allow blanking.

COMP fields (binary/computational) can be reference modified in COBOL. Reference modification extracts substrings and works on any data item, including computational fields.

COMP-3 (packed decimal) stores 2 digits per byte, with the last byte holding 1 digit plus sign. Storage bytes = (digits/2) + 1, where n is the number of digits in S9(n). For example, S9(5) needs 5/2 + 1 = 3 bytes.

QSAM (queued sequential access method) files support recording modes F (fixed), V (variable), U (undefined), and S (spanned). Options A (F,V) and B (U,S) are both valid recording mode sets.

Only the Identification Division is mandatory in every COBOL program. It contains the program identifier and is required for compilation. Environment, Data, and Procedure Divisions may be omitted in minimal programs.

Only the Identification Division is mandatory in every COBOL program. It contains the program identifier and is required for compilation. Environment, Data, and Procedure Divisions may be omitted in minimal programs.

The BLANK WHEN ZERO clause can only be applied to numeric or numeric-edited elementary items. It is invalid for level 66 (RENAMES) and level 88 (condition-name) items, and it cannot be specified for signed numeric items as it conflicts with sign representation.

The EJECT statement in COBOL is specifically designed to force a new page in compiler listings, similar to a page break in document formatting. This is a standard compiler-directing statement that controls output pagination. Option A correctly identifies this functionality.

The REWRITE statement in COBOL is used to update an existing record in a file. To replace a record, the file must be opened in I-O (Input-Output) mode, which allows both reading and writing. Opening in INPUT or OUTPUT modes is insufficient for updates.

VSAM (Virtual Storage Access Method) files manage their own cataloging and organization internally, unlike traditional sequential or indexed files that rely on LABEL RECORDS clauses. The LABEL RECORDS clause is ignored for VSAM files because VSAM handles file labeling through its own catalog mechanism. Option A is correct.

COMP (computational) fields store data in binary format, not as character strings. Reference modification in COBOL operates on character-based data, extracting substrings by position. Since COMP fields contain binary representations rather than displayable characters, they cannot be reference-modified directly. Option B (False) is correct because COMP fields can indeed be reference-modified if you understand their internal representation.

ASCENDING and DESCENDING keys are used for sorting and table searching operations (SORT, SEARCH ALL). Floating-point numbers are approximate values and may have tiny representation errors, making them unreliable for exact comparisons required by these operations. Therefore, floating-point items cannot be used as sort/search keys. Option A is correct.

SEARCH ALL uses a binary search algorithm, which requires the table to be sorted in a known order (ASCENDING or DESCENDING). Additionally, for binary search to work correctly and predictably, each key value must be unique so the search can definitively locate a single occurrence. Option A correctly states both requirements.

In COBOL, the EVALUATE statement requires at least one WHEN phrase to specify the conditions under which statements are executed. An EVALUATE statement containing no WHEN phrases is syntactically invalid, so the statement is false.

COBOL supports multiple open modes including INPUT, OUTPUT, I-O, and EXTEND, as well as file access modes like SEQUENTIAL, RANDOM, and DYNAMIC. Restricting file access or open methods to only INPUT and OUTPUT is incorrect, making the statement false.