Stream flatMapToInt() in Java with examples
Stream flatMapToInt(Function mapper) returns an IntStream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element. Stream flatMapToInt(Function mapper) is an intermediate operation. These operations are always lazy. Intermediate operations are invoked on a Stream instance and after they finish their processing, they give a Stream instance as output.
Note : Each mapped stream is closed after its contents have been placed into this stream. If a mapped stream is null, an empty stream is used, instead.
IntStream flatMapToInt(Function<? super T, ? extends IntStream> mapper) Where, IntStream is a sequence of primitive int-valued elements and T is the type of stream elements. mapper is a stateless function which is applied to each element and the function returns the new stream.
Example 1 : flatMapToInt() function with operation of parsing string to Integer.
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Example 2 : flatMapToInt() function with operation of mapping string with their length.
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