Java ArrayList trimToSize()

In this tutorial, we will learn about the Java ArrayList trimToSize() method, and learn how to use this method to trim this ArrayList to be its current size, with the help of examples.

Java ArrayList trimToSize() method

ArrayList trimToSize() trims the capacity of this ArrayList instance to be the list’s current size.

Syntax

The syntax of trimToSize() method is

ArrayList.trimToSize()

Returns

The method returns void.

1. trimToSize() – Trim ArrayList to specific size

In this example, we will initialize an ArrayList with four string elements "a", "b", "c" and "d". We will trim the capacity of this ArrayList to its size, which is four, using ArrayList trimToSize() method.

Java Program

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

public class Example {
	public static void main(String[] args) {
		ArrayList<String> arrayList = new ArrayList<String>(
				Arrays.asList("a", "b", "c", "d"));
		arrayList.trimToSize();
		System.out.println("ArrayList is trimmed to its size.");
	}
}

Output

ArrayList is trimmed to its size.

Conclusion

In this Java Tutorial, we have learnt the syntax of Java ArrayList trimToSize() method, and also learnt how to use this method with the help of Java example programs.