Topic 11. Lambda expressions, higher-order functions, collection operations, and sequences

Goal: learn to pass behavior as functions, build testable data pipelines, work with closures, and determine the limits of lazy evaluation.

Lecture contents

1. Function types and lambdas — Function types · Lambda syntax · Example 1. A calculator with a map of operations
2. Closures and inline functions — Closures and the lifetime of state · Inline and return control
3. Scope functions — Lambdas with a receiver and scope functions
4. Collection operations — Transformation and filtering · Grouping, indexes, and folding
5. Sequences and SAM interfaces — Sequences and lazy processing · Functional interfaces and Java SAM

Practice and review

• Practice — 3 worked examples with complete code
• Tasks — 30 variants, each with tasks at three difficulty levels
• Summary — conclusions, self-check questions, and useful links