# 如何在 Java 中查找`ArrayList`的长度

> 原文： [https://beginnersbook.com/2013/12/how-to-find-length-of-arraylist-in-java/](https://beginnersbook.com/2013/12/how-to-find-length-of-arraylist-in-java/)

通过使用`ArrayList` `size()` `ArrayList`类的方法，我们可以很容易地确定`ArrayList`的大小。此方法返回[`ArrayList`](https://beginnersbook.com/2013/12/java-arraylist/)的元素数。

`public int size()`

**示例：**

```java
package beginnersbook.com;
import java.util.ArrayList;
public class Details
{
    public static void main(String [] args)
    {
        ArrayList<Integer> al=new ArrayList<Integer>();
        System.out.println("Initial size: "+al.size());
        al.add(1);
        al.add(13);
        al.add(45);
        al.add(44);
        al.add(99);
        System.out.println("Size after few additions: "+al.size());
        al.remove(1);
        al.remove(2);
        System.out.println("Size after remove operations: "+al.size());
        System.out.println("Final ArrayList: ");
        for(int num: al){
            System.out.println(num);
        }
   }
}
```

输出：

```java
Initial size: 0
Size after few additions: 5
Size after remove operations: 3
Final ArrayList: 
1
45
99
```