JavaSE_List&Array_Java1.7

时间:2023-03-09 13:08:29
JavaSE_List&Array_Java1.7

这里简单写了下List和Array的相互转换

 package cn.rocker.collection.list;

 import org.junit.Test;

 import java.util.ArrayList;
import java.util.Arrays;
import java.util.List; /**
* @author rocker
* @version V1.0
* @Description:
* @date 2018/5/7 21:01
*/
public class ArrayListDemo1 {
@Test
/**
* @Description: ArrayList转换成数组
* @auther: rocker
* @date: 2018/5/7 21:20
*/
public void test1(){
List<Object> list = new ArrayList<>();
list.add(6);
list.add(2);
list.add(7);
list.add(4);
//list转成数组
Object[] objects = list.toArray();
//对转换后的数组进行排序
Arrays.sort(objects);
System.out.println(Arrays.toString(objects));
} @Test
/**
* @Description: 数组转换成List,
* 需要注意的是asList(arr)的参数arr的元素不能为基本类型
* short|int|long|float|double|byte|char|boolean
* @auther: rocker
* @date: 2018/5/7 21:20
*/
public void test2(){
int[] arr1 = {1,2,3};
List<int[]> list = Arrays.asList(arr1);
System.out.println(list.size()); char[] arr2 = {'a','b','c'};
List<char[]> chars = Arrays.asList(arr2);
System.out.println(chars.size()); String[] arr3 = {"d","e","f"};
List<String> strings = Arrays.asList(arr3);
System.out.println(strings.size());
}
}

JavaSE_List&Array_Java1.7