--- title: "Explain the Linq Concat() with C#." description: "Explain the Linq Concat() with C#." author: "Ashutosh Patel" published: 2025-02-12 updated: 2025-03-17 canonical: https://www.mindstick.com/forum/161159/explain-the-linq-concat-with-c-sharp category: "linq" tags: ["linq", "linq function"] reading_time: 2 minutes --- # Explain the Linq Concat() with C#. [Explain](https://www.mindstick.com/forum/157854/what-is-system-debugging-explain-some-system-debugging-tools-used-in-modern-computer-systems) the Linq Concat() with C#. ## Replies ### Reply by Khushi Singh LINQ in C# provides `Concat()` for merging two sequences (collections) into a single sequence with a retention of duplicate elements. The `Concat()` method resides within `System.Linq` namespace and functions with all objects that support `IEnumerable.` The Concat() method generates a brand new sequence from the original collections by including all elements according to their original appearance order. The [`Concat()`](https://www.mindstick.com/interview/23381/pros-and-cons-of-linq) method serves collection merger purposes especially when it is essential to preserve sequence information during the merging process. The `Concat()` method functions differently from Union() because it maintains all duplicated elements within two sequences. The operation proves useful when working with arranged datasets that need duplicated data items for processing. The main application of the `Concat()` functionality exists when various datasets need combination to perform operations like filtering, sorting or aggregations. The function finds wide applications in the process of combining similar entity lists which both retain their original sequence order like bringing together customer or product or transaction lists without altering the order. The `Concat()` method maintains all duplicates in the data and developers should check whether duplications were intended. After concatenation the application of Distinct() operator on the new sequence will help exclude duplicates to obtain a distinct record set. The `Concat()` method should be evaluated according to performance standards when handling big datasets since it generates new sequences without altering existing sequences. Developers gain effective sequence merging ability through the `Concat()` method because it allows complete control of data structure and sequence order in LINQ-based programming environments. --- Original Source: https://www.mindstick.com/forum/161159/explain-the-linq-concat-with-c-sharp Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.