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Java Stream map() vs flatMap()
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Java 8 introduced the Stream API, which brought a powerful way to process collections using a functional programming style. Two of the most frequently used methods in this API are map() and flatMap().
At first glance, both seem similar — they transform data. But their behavior differs when it comes to dealing with nested structures like List<List<T>>.
In this article, we’ll explore the key differences between map() and flatMap() using simple explanations, a comparison table, and complete examples with output.
