UNDERSCORE framework in the Java Library's application case analysis

UNDERSCORE framework in the Java Library's application case analysis Summary: Underscore is a Java class library for functional programming. It provides a set of powerful functions and tools that can simplify the development of developers in processing collection, iteration and function operation.This article will introduce the application cases of the Underscore framework in the Java class library and provide some specific Java code examples. 1. Collection operation UNDERSCORE provides many convenient methods to operate the collection, such as filtering, mapping and sorting.Here are some example code: // Filter: Only retain string with greater length greater than 5 List<String> filteredList = _.filter(list, s -> s.length() > 5); // Map: Convert the string set to a capitalization List<String> upperList = _.map(list, String::toUpperCase); // Sorting: Sort by the length of the string List<String> sortedList = _.sortBy(list, String::length); 2. iteration operation UNDERSCORE provides powerful tools for iterative collection, such as Foreach, Reduce, and Groupby.Here are some example code: // Foreach: Each element in the print collection _.forEach(list, System.out::println); // Reduce: Find the sum of the integer in the collection int sum = _.reduce(integerList, (acc, num) -> acc + num, 0); // Groupby: According to age groupers Map<Integer, List<Person>> groupedPeople = _.groupBy(peopleList, Person::getAge); 3. Function operation UNDERSCORE supports transmitting functions as parameters to other functions, which is very common in functional programming.Here are some example code: // Function combination: combine two functions Function<Integer, Integer> multiplyByTwo = x -> x * 2; Function<Integer, Integer> addThree = x -> x + 3; Function<Integer, Integer> combinedFunction = _.compose(multiplyByTwo, addThree); int Result = CombineDFunction.apply (5); // The result is 16 // Corride: Convert the multi -parameter function to a series of single -parameter functions Function<Integer, Function<Integer, Integer>> curriedFunction = _.curry((x, y) -> x * y); int partialResult = CurrowFunction.apply (2) .apply (3); // The result is 6 Conclusion: The UNDERSCORE framework is a powerful Java class library that provides many functional programming tools and methods that can greatly simplify the development of developers in processing collection, iteration and function operations.By using Underscore, developers can write elegant and simple code more efficiently.