100 DataWeave Problems: Array Transformations map, filter, reduce, orderBy, groupBy | Volume 4
Array Transformations
100 Hands-On Problems for Mastering DataWeave Array Processing & Transformation
Arrays are everywhere in real-world MuleSoft integrations—customer lists, orders, products, transactions, employees, API responses, database records and more.
This volume focuses entirely on array transformations in DataWeave 2.0, giving you 100 practical problems designed to build strong problem-solving skills.
Instead of learning array functions in isolation, you'll use them to solve realistic transformation requirements and business scenarios.
📚 What's Inside
100 practical DataWeave problems covering:
- map
- mapObject
- filter
- filterObject
- reduce
- orderBy
- groupBy
- distinctBy
- flatten
- flatMap
- pluck
- joinBy
- contains
- Array slicing
- Array concatenation
- Array sorting
- Array grouping
- Nested array transformations
- Complex array combinations
🛠️ Real-World Problems
Practice scenarios such as:
- Transforming customer lists
- Filtering active customers
- Finding high-value orders
- Calculating totals with reduce
- Sorting products by price
- Grouping transactions by customer
- Removing duplicate records
- Flattening nested API responses
- Extracting values from complex arrays
- Joining array values
- Combining multiple arrays
- Processing nested order items
- Finding matching records
- Applying multiple transformations together
💡 Every Problem Includes
Scenario → Input → Requirement → DataWeave Code → Output → Explanation
This makes the book useful both as a learning guide and as a hands-on DataWeave practice workbook.
🎯 What You'll Learn
By completing these 100 problems, you'll learn how to:
- Transform every element of an array with map
- Select records using filter
- Aggregate array data using reduce
- Sort data with orderBy
- Group records using groupBy
- Remove duplicates with distinctBy
- Flatten nested arrays
- Extract values with pluck
- Combine arrays using zip and zipWith
- Search arrays efficiently
- Check array conditions
- Slice and reshape arrays
- Work with deeply nested arrays
- Combine multiple array functions
- Build production-style DataWeave transformations
📈 Progressive Difficulty
The problems gradually move from beginner → intermediate → advanced.
You'll start with straightforward array transformations and progress toward problems requiring multiple functions and complex nested data.
👨💻 Who Is This For?
Perfect for:
- MuleSoft Developers
- DataWeave Developers
- Integration Developers
- MuleSoft Interview Candidates
- DataWeave Beginners
- Developers preparing for DataWeave coding rounds
- Professionals working with complex API and database payloads
🚀 Why This Book?
If you work with MuleSoft, you'll constantly encounter arrays.
The real challenge isn't knowing that map or filter exists—it's knowing which function to use, how to combine functions, and how to transform complex nested data correctly.
This volume gives you 100 opportunities to practice exactly that.
Learn the function. Solve the problem. Understand the output. Build the skill.
📖 Part of the 1000 DataWeave Problems with Solutions Series
Volume 4 — Array Transformations
100 Problems • 100 Solutions • Real Integration Scenarios
Build your DataWeave expertise one array problem at a time.
