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layout: page
title: Lambda Functions
keywords: ksqldb, function, udf, lambda
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# Lambda Functions

Use lambda functions, or "lambdas" for short, to express simple inline functions that can be applied to input values in various ways.
For example, you could apply a lambda function to each element of a collection, resulting in a transformed output collection. 
Also, you can use lambdas to filter the elements of a collection, or reduce a collection to a single value.
The advantage of a lambda is that you can express user-defined functionality in a way that doesn’t require implementing a full [UDF](/how-to-guides/create-a-user-defined-function).

Learn how to use lambda functions in the [how-to guide](/how-to-guides/use-lambda-functions).
