What is a Java stream?

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Accepted Answer

Java Streams provide a functional approach to processing sequences of elements, enabling efficient data manipulation and transformation.

Streams are not data structures; they are views of data that can be processed in a functional style.
They support operations like filter, map, and reduce for transforming data. Example: list.stream().filter(x -> x > 10).collect(Collectors.toList()).
Streams can be sequential or parallel, allowing for optimized performance on large datasets.
They are lazy; operations are not executed until a terminal operation (like collect) is invoked.
Streams can be created from collections, arrays, or I/O channels. Example: Stream.of(1, 2, 3).map(x -> x * 2).forEach(System.out::println).

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