Master Mainframe Technologies - COBOL, JCL, DB2, VSAM, CICS & More
ABEND Codes SQLCODEs File Status Interview Prep Contact

Practice Problems

Master COBOL, JCL, and mainframe skills with real-world scenarios

109
Total Problems
38
Beginner
47
Intermediate
24
Advanced

📝 String Handling

Advanced
COBOL
Parse a comma-separated record into individual fields. Input: "JOHN,DOE,35,NEW YORK"...
unstring csv parsing delimited

📁 File Handling

COBOL
Read two sorted files and merge them into one sorted output file....
file merge sort algorithm
COBOL
Update master file with transactions: A=Add, U=Update, D=Delete. Both files sorted by key....
file master transaction batch
COBOL
Use REPORT WRITER to generate formatted report....
report formatting output
COBOL
Generate report with control breaks (subtotals by group)....
control-break subtotal report

🔗 Subprograms

COBOL
Understand difference between BY REFERENCE and BY CONTENT....
call reference content value

⚙️ JCL Basics

COBOL
Read VSAM KSDS file sequentially....
vsam ksds sequential indexed
Advanced
COBOL
Read VSAM KSDS randomly by key....
vsam ksds random direct-access
COBOL
Add new records and update existing records in KSDS....
vsam write rewrite update

🛠️ JCL Utilities

Advanced
JCL
Write JCL to create a new generation of a GDG and also reference the previous generation....
gdg generation versioning
JCL
Create and call a JCL procedure....
proc procedure symbolic override
JCL
Create job where step execution depends on previous step outcome....
jcl if-then conditional multi-step

🏢 Real-World Scenarios

COBOL
Calculate gross pay, deductions, and net pay. Regular hours up to 40, overtime at 1.5x....
payroll business calculation
COBOL
Read employee file, calculate tax based on salary slabs, generate formatted salary report. Tax Slabs: 0-25000: 0%, 25001-50000: 10%, 50001-100000: 20%...
payroll report tax evaluate
COBOL
Track product inventory: add stock, sell items, show low stock alerts (below 10 units), generate inventory report....
inventory tables business menu
Advanced
COBOL
Simulate ATM: PIN verification (3 attempts), check balance, withdraw (multiples of 100, max 20000), deposit, mini statement (last 5 transactions)....
atm banking security transactions
Advanced
COBOL
Generate itemized bill: multiple items with quantity and price, apply discount if total > 1000, add GST 18%, print formatted bill....
billing invoice business calculation
COBOL
Manage student records: add students, record marks for 5 subjects, calculate total/average/grade, show class topper....
grades students tables business
COBOL
Process customer orders: validate customer ID, check product availability, calculate total, apply loyalty discount, update inventory....
order ecommerce business validation
COBOL
Generate monthly bank statement: opening balance, all transactions, closing balance, interest calculation....
banking statement running-balance interest
COBOL
Calculate insurance premium based on age, coverage amount, and risk factors....
insurance premium risk calculation
COBOL
Track employee leave: apply leave, approve/reject, show balance, generate leave report....
leave hr employee management
COBOL
Manage patient records: admit, discharge, view details, bill calculation....
hospital patient healthcare billing
COBOL
Manage library: add books, issue, return, check availability, fine calculation....
library books management fine