foldLeft

Lesson in the Scala Roadmap · Stage 9: Working with Strings

Last updated 14 September 2026

What is foldLeft?

The foldLeft method is used to produce a single result by "folding" all the elements of a collection. The algorithm starts with a "zero" element which is paired with the first element of the collection to create an intermediate result element. Then that intermediate result is paired with the second element of the collection to create a new intermediate result, and so on, until the algorithm reaches the end of the collection. Then the final result is returned.

Study this in the interactive course See the whole Scala roadmap

Free resources to learn foldLeft

ArticleScala Collections - FoldLeft Method
ArticleFolding Lists in Scala | Baeldung on Scala
ArticleScala Tutorial - FoldLeft Function Example

foldLeft: common questions

Can I learn foldLeft in Hindi?

This lesson is written in English. Once you sign in, open it in the interactive course and ask the AI tutor to explain foldLeft in Hindi or Hinglish. The tutor answers from this lesson’s own text, so it stays on the syllabus, and it runs on your own Google, OpenAI or Anthropic key.

Is this foldLeft tutorial for beginners?

It is lesson 50 of 165 in the free Scala roadmap, in stage 9, Working with Strings. If you are new to Scala, start from stage 1 and come back here in order; if you already know the earlier stages, this lesson stands on its own.