--- title: Obtain Index of a Given LinkedHashSet Element Without... description: LinkedHashSet maintains uniqueness and order but lacks efficient index-based lookups (O(n) time). Several approaches exist: direct iteration, converting to... canonical: https://daily.dev/posts/obtain-index-of-a-given-linkedhashset-element-without-iteration-6gnidgkj4 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Obtain Index of a Given LinkedHashSet Element Without Iteration | daily.dev og:description: LinkedHashSet maintains uniqueness and order but lacks efficient index-based lookups (O(n) time). Several approaches exist: direct iteration, converting to... og:url: https://daily.dev/posts/obtain-index-of-a-given-linkedhashset-element-without-iteration-6gnidgkj4 og:image: https://api.daily.dev/og/posts/6gnIdGkJ4.png og:image:alt: Obtain Index of a Given LinkedHashSet Element Without Iteration og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Obtain Index of a Given LinkedHashSet Element Without Iteration **[Baeldung](https://daily.dev/sources/baeldung)** · 8 min read · 0 upvotes · 0 comments ## Summary LinkedHashSet maintains uniqueness and order but lacks efficient index-based lookups (O(n) time). Several approaches exist: direct iteration, converting to List/array (still O(n) for indexOf), maintaining separate List+Set structures, or building a custom implementation with dual maps for O(1) lookups. The custom approach with element-to-index and index-to-element maps offers the best performance for frequent index queries, though removal requires reindexing (O(n)). Choice depends on operation frequency, dataset size, and whether you prioritize additions, removals, or lookups. Thread safety requires synchronization when coordinating multiple data structures. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Select a Random Key from a HashMap in Java](https://daily.dev/posts/select-a-random-key-from-a-hashmap-in-java-wtnq6cb5t) · Baeldung · 0 upvotes · 0 comments - [The Dictionary Problem: How Do You Efficiently Look Up Things?](https://daily.dev/posts/the-dictionary-problem-how-do-you-efficiently-look-up-things--txhixcvpo) · The Polymathic Engineer · 1 upvotes · 0 comments - [On programming, statistics, and Java](https://daily.dev/posts/on-programming-statistics-and-java-8d0gstmw0) · Awesome Java Newsletter · 0 upvotes · 0 comments --- Tags: [#performance](https://daily.dev/tags/performance), [#java](https://daily.dev/tags/java), [#algorithms](https://daily.dev/tags/algorithms), [#data-structures](https://daily.dev/tags/data-structures) [View this post on daily.dev](https://daily.dev/posts/obtain-index-of-a-given-linkedhashset-element-without-iteration-6gnidgkj4) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Obtain Index of a Given LinkedHashSet Element Without Iteration","url":"https://daily.dev/posts/obtain-index-of-a-given-linkedhashset-element-without-iteration-6gnidgkj4","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/obtain-index-of-a-given-linkedhashset-element-without-iteration-6gnidgkj4"},"datePublished":"2026-01-10T03:45:18.367Z","dateModified":"2026-01-10T03:46:06.595Z","description":"LinkedHashSet maintains uniqueness and order but lacks efficient index-based lookups (O(n) time). 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