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OCaml / Collections

List.filter

Learn List.filter in OCaml with a construct-specific explanation, unique example, engineering boundary, and mastery check.

10 min read • Intermediate

List.filter is a focused OCaml topic inside Collections. This lesson explains the construct itself, the state or value it operates on, and the observable result it produces.

Read the example as a small executable experiment. Identify the exact syntax that belongs to List.filter, then change one input and predict the result before running it.

Topic-specific example

ocaml-04-04-list-filter.ml
ocaml Try It Live 
let evens = List.filter (fun x -> x mod 2 = 0) [1;2;3;4]
Edge case / engineering note

List.filter has rules that are easy to miss when the example is copied mechanically. Check the feature-specific boundary shown by this construct: scope, mutability, evaluation order, type constraints, lifetime, error behavior, compile-time restrictions, or resource cleanup where applicable.

Content source & attribution
Original Syntaxis Content · Original Syntaxis Content

Lesson quizzes

List.filter Mastery Check →
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