CUCO study guide
CUCO · Work through your exam, one topic at a time.
CUCO is a multiple-choice certification exam in COBOL programming, aimed at developers who write, maintain, or modernize mainframe and COBOL-based business systems. It tests whether you can read and reason about COBOL source code rather than recall trivia: how the language's divisions fit together, how data is described and stored, how control flow executes, how files are processed, and how tables and subprograms behave. The CUCO study guide has 7 sections and about 3,104 words.
01Fundamentals of COBOL Programming
The Fundamentals domain tests whether you can read the skeleton of a COBOL program and spot what will fail before execution: division order, source-format columns, naming, and sentence structure. Exam items typically show a short source fragment and ask which line is illegal or which division owns a clause.
462 words, about 2 min02Data Division and Data Description
The Data Division domain tests whether you can describe storage precisely: level structure, PICTURE character strings, USAGE clauses, VALUE and REDEFINES rules, and the lifetime of each section. Exam items often ask for the byte length of a field or the effect of a MOVE between two descriptions.
468 words, about 2 min03Procedure Division and Control Structures
The Procedure Division domain tests control flow: how PERFORM executes paragraphs, how conditions and EVALUATE select paths, and how arithmetic and string statements report errors. Items often ask how many times a loop runs or where control resumes after an END-IF.
408 words, about 2 min04File Handling and I/O Operations
The File Handling domain tests whether you can declare a file correctly and use the right I/O verb for its organization and open mode. Exam items ask which status code appears, why a REWRITE failed, or what ACCESS MODE permits.
419 words, about 2 min05Tables, Arrays, and Subprograms
This domain tests fixed and variable-length tables, the difference between subscripts and indexes, serial versus binary search, and the CALL interface between programs. Items often ask why SEARCH ALL returned the wrong entry or why a caller's field did not change.
456 words, about 2 min06Debugging, Testing, and Maintenance
This domain tests how you find and fix defects: compiler options, runtime abend diagnosis, test-data design, and safe maintenance of working code. Items often present a failure symptom and ask for the most likely cause or the option that would have caught it.
445 words, about 2 min07Modern COBOL and Integration
This domain tests how current COBOL programs interact with modern platforms: newer language features, JSON and XML generation, SQL and transaction processing, and cross-language calls. Items often ask which clause is required for a valid JSON name or what SQLCODE 100 means.
446 words, about 2 min