# Functional Programming in Java, Second Edition: On page 27, after "Found 2 names"

**URL:** <https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354>\
**Category:** PragProg Customers\
**Tags:** book-functional-programming-in-java-second-edition, errata\
**Created:** [17 May 2023 11:37 UTC](https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354 "2023-05-17T11:37:09Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![dtonhofer](https://forum.devtalk.com/user_avatar/forum.devtalk.com/dtonhofer/32/3389_2.png) [@dtonhofer](https://forum.devtalk.com/u/dtonhofer)\
**Post date:** [17 May 2023 11:37 UTC](https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354/1 "2023-05-17T11:37:09Z")

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On p.27, after “Found 2 names”, we read:

```auto
The filter() method returns an iterator just like the map() method does, 

```

But it really returns a `Stream` for further processing, not an iterator.

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**Author:** ![venkats](https://forum.devtalk.com/user_avatar/forum.devtalk.com/venkats/32/508_2.png) [@venkats](https://forum.devtalk.com/u/venkats)\
**Post date:** [31 May 2023 18:03 UTC](https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354/2 "2023-05-31T18:03:31Z")

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You are correct that it returns a Stream but streams are internal iterators. Keeping the text as is.

Thank you.

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<div class="post-metadata">

**Author:** ![dtonhofer](https://forum.devtalk.com/user_avatar/forum.devtalk.com/dtonhofer/32/3389_2.png) [@dtonhofer](https://forum.devtalk.com/u/dtonhofer)\
**Post date:** [2 June 2023 08:52 UTC](https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354/3 "2023-06-02T08:52:29Z")

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Thank you,

Could one add a note that “stream” instances are also called “internal iterators”?

It is not fully evident to me.

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**Author:** ![venkats](https://forum.devtalk.com/user_avatar/forum.devtalk.com/venkats/32/508_2.png) [@venkats](https://forum.devtalk.com/u/venkats)\
**Post date:** [2 June 2023 09:19 UTC](https://forum.devtalk.com/t/functional-programming-in-java-second-edition-on-page-27-after-found-2-names/109354/4 "2023-06-02T09:19:43Z")

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Good suggestion. Will do. Thank you.