High -efficiency programming techniques based on the Underscore framework in the Java library

High -efficiency programming techniques based on the Underscore framework in the Java library In Java programming, the use of efficient libraries and frameworks can greatly improve the quality of code and development efficiency.UNDERSCORE is a functional programming style Java class library. It provides some powerful and concise tools and functions that allow us to process sets and data in a more effective way. 1. Basic introduction The author of the UNDERSCORE class library was inspired by the UndersCore.js library of JavaScript, perfecting the thought of functional programming with Java.It provides many commonly used tools and functions, such as mapping, filtering, iteration, etc., which can make our code simpler and elegant. 2. Import Underscore class library First, we need to import the Underscore class library in the project.You can use Maven or Gradle and other construction tools to add it to the dependence of the project, or you can download the jar package manually and add it to the project. Third, basic usage of Underscore Below we will introduce several high -efficiency programming techniques based on the UNDERSCORE class library: 1. Filter collection Underscore provides the Filter method to quickly filter the elements in the collection.For example, we must filter out all the even numbers from an integer list: import com.github.underscore.$; List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9); List<Integer> evenNumbers = $.filter(numbers, n -> n % 2 == 0); By using the $. Filter method, we only need to provide a lambda expression as the filter condition to easily get a list containing all the even numbers. 2. Map collection Underscore's MAP method can map each element in a collection.For example, we can convert each element in a string list into uppercase forms: import com.github.underscore.$; List<String> words = Arrays.asList("hello", "world"); List<String> upperCaseWords = $.map(words, String::toUpperCase); By using the $ .map method, we can pass a lambda expression or method reference to customize each element in the set. 3. Capsule of the collection element The Reduce method of Underscore can return all the elements in a collection according to the specified rules.For example, we can calculate the sum of an integer list through the Reduce method: import com.github.underscore.$; List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5); int sum = $.reduce(numbers, (acc, n) -> acc + n, 0); In the above example, we specify a initial accumulator value to 0, and each element is added to the accumulator through Lambda expression, so as to get the sum of the entire list. Fourth, summary The Underscore class library provides a simple and powerful programming method for Java developers. Through several examples, we can see its advantages when processing collection and data.Using Underscore class libraries, we can efficiently process sets and data through methods such as Filter, Map, Reduce, etc., so that our code is more concise and readable. For Java developers, the use of Underscore class libraries will allow us to do more with less in daily development.I hope this article can help you better understand the UNDERSCORE class library and be applied in actual projects.