# 如何在 Java 中查找`ArrayList`的長度 > 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/) 通過使用`ArrayList` `size()` `ArrayList`類的方法，我們可以很容易地確定`ArrayList`的大小。此方法返回[`ArrayList`](https://beginnersbook.com/2013/12/java-arraylist/)的元素數。 `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); } } } ``` 輸出： ```java Initial size: 0 Size after few additions: 5 Size after remove operations: 3 Final ArrayList: 1 45 99 ```