Java Utility Library

Java ArrayList - trimToSize() Method

The java.util.ArrayList.trimToSize() method is used to trim the capacity of the given ArrayList to be the list's current size. An application can use this operation to minimize the storage of an ArrayList instance.

Syntax

public void trimToSize()

Parameters

No parameter is required.

Return Value

void type.

Exception

NA.

Example:

In the example below, the java.util.ArrayList.trimToSize() method is used to trim the capacity of the given ArrayList to be the list's current size.

import java.util.*;

public class MyClass {
  public static void main(String[] args) {
    //creating an ArrayList with capacity 10
    ArrayList<Integer> MyList = new ArrayList<Integer>(10);

    //populating the ArrayList
    MyList.add(10);
    MyList.add(20);
    MyList.add(30);   
    MyList.add(40);

    //trim the capacity of the ArrayList to 4
    MyList.trimToSize();

    //print the content the ArrayList
    System.out.println("MyList contains: "+ MyList);
  }
}

The output of the above code will be:

MyList contains: [10, 20, 30, 40]

❮ Java.util - ArrayList