Question 1

What is the WRITE statement in COBOL?

Accepted Answer

The WRITE statement outputs a record to a file that has been opened for output or input-output. WRITE is used for file output operations, writing data records to files defined in the FILE SECTION. Unlike DISPLAY which outputs to the console, WRITE writes to files. The file must be defined in FILE-CONTROL, have an FD entry, be opened before writing, and the record must be moved to the record area before writing.

Question 2

What is the syntax of WRITE?

Accepted Answer

The basic syntax is: WRITE record-name [FROM identifier] [INVALID KEY imperative-statement] [NOT INVALID KEY imperative-statement] [END-WRITE]. The record-name is the 01-level item under the FD. FROM clause allows writing from a different field. INVALID KEY handles key errors for indexed files. END-WRITE is an explicit scope terminator (optional if END-WRITE is not needed for structured programming).

Question 3

What is END-WRITE?

Accepted Answer

END-WRITE is an explicit scope terminator for the WRITE statement. It marks the end of the WRITE statement's scope, particularly useful when WRITE has associated INVALID KEY or NOT INVALID KEY clauses. END-WRITE is optional in many contexts but recommended for structured programming and clarity. It pairs with WRITE to create a clear block structure.

Question 4

How do you write to a sequential file?

Accepted Answer

For sequential files: 1) Define the file in FILE-CONTROL with ORGANIZATION IS SEQUENTIAL, 2) Define FD and record in FILE SECTION, 3) OPEN the file for OUTPUT or EXTEND, 4) MOVE data to the record area, 5) WRITE record-name, 6) Check file status if needed, 7) CLOSE the file. Sequential files write records in order, one after another.

Question 5

How do you write to an indexed file?

Accepted Answer

For indexed files: 1) Define with ORGANIZATION IS INDEXED and ACCESS MODE, 2) Specify RECORD KEY, 3) OPEN for OUTPUT or I-O, 4) MOVE data including key field, 5) WRITE with INVALID KEY clause to handle duplicate keys, 6) Check file status, 7) CLOSE. Indexed files allow random access by key and require unique keys (unless duplicates are allowed).

Question 6

What is the FROM clause in WRITE?

Accepted Answer

The FROM clause allows you to write from a different field than the record area. Syntax: WRITE record-name FROM identifier. This is equivalent to MOVE identifier TO record-name followed by WRITE record-name, but done in one statement. FROM is useful when you have data in a working storage field and want to write it directly without an explicit MOVE.

Question 7

What happens if you write a duplicate key to an indexed file?

Accepted Answer

If you attempt to write a record with a duplicate key to an indexed file (and duplicates are not allowed), the WRITE fails and the INVALID KEY condition is raised. The file status is set (typically "23" for duplicate key), and control goes to the INVALID KEY clause if specified. You must handle this condition, either by using a different key, updating the existing record, or reporting an error.

Question 8

Do you need to check file status after WRITE?

Accepted Answer

Yes, you should check file status after WRITE operations, especially for indexed files or when error handling is important. File status "00" means success, "23" means duplicate key (indexed files), "30" means permanent error, etc. While INVALID KEY handles some cases, checking file status provides comprehensive error information and is a best practice for robust file handling.

COBOL Tutorial

COBOL WRITE and END-WRITE

What is WRITE?

Basic Syntax

Writing to Sequential Files

Writing to Indexed Files

Using FROM Clause

File Status Checking

END-WRITE Scope Terminator

Best Practices

Test Your Knowledge

Related Concepts

Related Concepts

File Operations

OPEN Statement

READ Statement

File Status

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