Streams & lambdas in Java: interview exercises

Streams & lambdas in Java: 6 test-checked interview exercises (Squares of the even numbers), each beside a worked example, with tests as you go. Free.

1. Squares of the even numbers
2. Count the words
3. Flatten nested lists
4. Sort by two keys
5. Partition by a threshold
6. Rows to CSV

Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.

More Java topics

• Strings
• Collections
• Records, classes & interfaces
• Generics & Optional
• Exceptions & validation
• Algorithms & recursion
• Modern Java

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