Java输出数组的内容

1. 输出内容最常见的方式

// List类型的列表
List list = new ArrayList();
list.add("First");
list.add("Second");
list.add("Third");
list.add("Fourth");
System.out.println(list);

输出:
[First, Second, Third, Fourth]

// String数组
"code" class="java">String[] array = new String[] { "First", "Second", "Third", "Fourth" };
System.out.println(array.toString());

输出:
[Ljava.lang.String;@12dacd1

2. 使用Array类输出数组内容

// String数组
String[] array = new String[] { "First", "Second", "Third", "Fourth" };
System.out.println(Arrays.toString(array));

输出:
[First, Second, Third, Fourth]

3. 输出数组的数组

可以使用Arrays.deepToString()方法。

String[] arr1 = new String[] { "Fifth", "Sixth" };
String[] arr2 = new String[] { "Seventh", "Eight" };
// 数组的数组
String[][] arrayOfArray = new String[][] { arr1, arr2 };
// 比较下面的输出
System.out.println(arrayOfArray);
System.out.println(Arrays.toString(arrayOfArray));
System.out.println(Arrays.deepToString(arrayOfArray));

输出:
[[Ljava.lang.String;@1ad086a
[[Ljava.lang.String;@10385c1, [Ljava.lang.String;@42719c]
[[Fifth, Sixth], [Seventh, Eighth]]

再看下面的完整例子：

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


public class PrintArray {
    public static void main(String[] args) {
        List list = new ArrayList();
        list.add("First");
        list.add("Second");
        list.add("Third");
        list.add("Fourth");


        System.out.println(list);


        String[] array = new String[] { "First", "Second", "Third", "Fourth" };
        System.out.println(array.toString());
        System.out.println(Arrays.toString(array));


        String[] arr1 = new String[] { "Fifth", "Sixth" };
        String[] arr2 = new String[] { "Seventh", "Eigth" };
        String[][] arrayOfArray = new String[][] { arr1, arr2 };


        System.out.println(arrayOfArray);
        System.out.println(Arrays.toString(arrayOfArray));
        System.out.println(Arrays.deepToString(arrayOfArray));
    }
}

输出:

[First, Second, Third, Fourth]
[Ljava.lang.String;@12dacd1
[First, Second, Third, Fourth]
[[Ljava.lang.String;@1ad086a
[[Ljava.lang.String;@10385c1, [Ljava.lang.String;@42719c]
[[Fifth, Sixth], [Seventh, Eigth]]