# Java `ArrayList isEmpty()`方法

> 原文： [https://beginnersbook.com/2013/12/java-arraylist-isempty-method-example/](https://beginnersbook.com/2013/12/java-arraylist-isempty-method-example/)

`java.util.ArrayList`类的`isEmpty()`方法用于检查列表是否为空。此方法返回一个布尔值。

`public boolean isEmpty()`

如果列表为空则返回`true`，否则返回`false`。

### 例

```java
package beginnersbook.com;
import java.util.ArrayList;
public class IsEmptyExample {
  public static void main(String args[]) {
      //ArrayList of Integer Type
      ArrayList<Integer> al = new ArrayList<Integer>();
      //Checking whether the list is empty
      System.out.println("Is ArrayList Empty: "+al.isEmpty());

      //Adding Integer elements
      al.add(1);
      al.add(88);
      al.add(9);
      al.add(17);

      //Again checking for isEmpty
      System.out.println("Is ArrayList Empty: "+al.isEmpty());

      //Displaying elements of the list
      for (Integer num: al) {
      System.out.println(num);
   }
}
}
```

输出：

```java
Is ArrayList Empty: true
Is ArrayList Empty: false
1
88
9
17
```