How to use the UNDERSCORE framework in the Java library

The UNDERSCORE framework is a tool for operating collection and array in the Java class library.It provides a set of simple and powerful tools for operations such as screening, conversion, and aggregation of setting.This article will introduce the UNDERSCORE framework and provide some Java code examples. 1. Introduce the UNDERSCORE framework First, we need to introduce the dependencies of the UNDERSCORE framework in the project.It can be introduced through building tools such as Maven or Gradle.Below is a maven example configuration: <dependency> <groupId>com.github.javadev</groupId> <artifactId>underscore</artifactId> <version>1.62</version> </dependency> 2. Tools to use the Underscore framework The UNDERSCORE framework provides a wealth of tools for operating collection and array.Below we introduce a few commonly used methods: -` _.filter () `: It is used to screen elements that meet the conditions in the set.The following is an example of use: List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); List<Integer> evenNumbers = _.filter(numbers, n -> n % 2 == 0); System.out.println (EVENNUMBERS); // Output: [2, 4] -` _.map () `: It is used to convert the elements in the set.The following is an example of use: List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); List<Integer> squaredNumbers = _.map(numbers, n -> n * n); System.out.println (Squarednumbers); // Output: [1, 4, 9, 16, 25] -` _.Reduce () `: Used to aggregate the elements in the set.The following is an example of use: List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); int sum = _.reduce(numbers, (acc, n) -> acc + n, 0); System.out.println (SUM); // Output: 15 3. The function of extending the UNDERSCORE framework In addition to the basic tools provided, the UNDERSCORE framework also supports the expansion of its functions.We can create a custom chain operation by implementing the `ORG.UndersCore.chain.chain` interface.The following is an example of a custom chain operation: List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); Chain<Integer> chain = _.chain(numbers) .filter(n -> n % 2 == 0) .map(n -> n * n); List<Integer> result = chain.value(); System.out.println (result); // Output: [4, 16] Through the above code, we customized a chain operation, screened the set first, and then converted the screening results. Summarize: The UNDERSCORE framework is a convenient and powerful Java class library for operating collection and array.By introducing the dependencies of the UNDERSCORE framework and using the tools provided by it.By expanding the function of the Underscore framework, we can also create a custom chain operation.I hope this article will help you understand the UNDERSCORE framework.