java小妙招:List和数组互转

笔记 / 2021-09-16

数组转换List

Arrays.stream(arr).boxed().collect(Collectors.toList());

// 数组转 list
int arr [] ={1,2,4,3,28,22};
Arrays.sort(arr);
// 通过stream进行转换    
Arrays.stream(arr).boxed().collect(Collectors.toList()).forEach(System.out::println);

List转数组

Arrays.asList().toArray(new Integer[SIZE])

// lsit 转 数组
List<Integer> integers = Arrays.asList(1, 2, 3, 4, 5, 6);
Integer[] ints = integers.toArray(new Integer[(integers.size())]);
for (Integer anInt : ints) {
	System.out.println(anInt);
}

完整代码

package exec;

import base.Array;

import java.util.ArrayList;
import java.util.Arrays;

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

public class ExecTest {
    public static void main(String[] args) {
        // 数组转 list
        int arr [] ={1,2,4,3,28,22};
        Arrays.sort(arr);
        // 通过stream进行转换
        Arrays.stream(arr).boxed().collect(Collectors.toList()).forEach(System.out::println);

        // lsit 转 数组
        List<Integer> integers = Arrays.asList(1, 2, 3, 4, 5, 6);
        Integer[] ints = integers.toArray(new Integer[(integers.size())]);
        for (Integer anInt : ints) {
            System.out.println(anInt);
        }
    }

}