[Java知识库]Java/Rust stream流

Java/Rust stream流

Java

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Stream {
    public static void main(String[] args) {

        ArrayList<student> students = new ArrayList<>();
        students.add(new student(1, "lzw"));
        students.add(new student(1, "lzw"));
        students.add(new student(2, "lzww"));
        students.add(new student(3, "lzwww"));
        students.add(new student(4, "lzwwww"));
        students.add(new student(5, "lzwwwww"));


        //filter
        System.out.println(students.stream().filter(x -> x.getId() > 3).collect(Collectors.toList()));

        //distinct去除重复元素
        System.out.println(students.stream().distinct().collect(Collectors.toList()));

        //forEach
        students.stream().forEach(System.out::println);

        //map
        System.out.println(students.stream().map(s -> {
            s.setId(s.getId() + 1);
            return s;
        }).collect(Collectors.toList()));


    }
}

Rust

fn main() {

    #[derive(Debug,Clone)]
    struct student{
        name: String,
        id: u64,
    }

    let mut students:Vec<student> = vec![];
    for i in 1..5{
        students.push(student {
            name: "lzw".to_string(),
            id: i,
        });
    }

		//map
    let x = students.clone().into_iter().map(|mut x1| {
        x1.id += 1;
        x1
    }).collect::<Vec<_>>();
    println!("{:?}",x);
		
  	//filter
    let vec1 = students.into_iter().filter(| x2| {
        if x2.id == 2 {
            true
        }else {
            false
        }
    }).collect::<Vec<_>>();
    println!("{:?}",vec1);

}