Flash cards
Review the key moves
1/4
Core idea
What is the main idea behind Java ArrayList clone() Method?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
1Quick choice
Which statement best captures the main point of this lesson?
2Fill blank
Complete the missing token from the example code.
___ java.util.ArrayList;3Order
Put the learning moves in the order that makes the concept easiest to apply.
The clone() method returns a copy of the ArrayList as an Object .
Definition and Usage
Java ArrayList clone() Method
❮ ArrayList Methods
Example
import java.util.ArrayList;
public class Main {
public static void main(String[] args) {
ArrayList<String> cars = new ArrayList<String>();
cars.add("Volvo");
cars.add("BMW");
cars.add("Ford");
cars.add("Mazda");
ArrayList cars2 = (ArrayList)cars.clone();
cars2.set(0, "Toyota");
System.out.println(cars);
System.out.println(cars2);
}
}Definition and Usage
The clone() method returns a copy of the ArrayList as an Object .
This creates a "shallow" copy, which means that copies of objects in the list are not created, instead the list has references to the same objects that are in the original list.
Note
Since the return type is Object , it must be type casted in order to use it as an ArrayList as shown in the example above.
Syntax
public Object clone()Technical Details
| Returns: | A copy of the ArrayList object. |
|---|