remplir list Java rapidemnet
To fill a list in Java quickly, you can use the addAll
method from the java.util.Collections
class. This method allows you to add all elements from another collection to an existing list. Here's an example:
import java.util.ArrayList;
import java.util.List;
import java.util.Collections;
public class FillListExample {
public static void main(String[] args) {
List<String> list = new ArrayList<>();
// Create a separate collection with elements to add
List<String> elementsToAdd = new ArrayList<>();
elementsToAdd.add("Element 1");
elementsToAdd.add("Element 2");
elementsToAdd.add("Element 3");
// Use the addAll method to fill the list quickly
Collections.addAll(list, elementsToAdd.toArray(new String[0]));
// Print the filled list
System.out.println(list);
}
}
In this example, we first create an empty ArrayList
called list
. Then, we create another ArrayList
called elementsToAdd
and add the elements that we want to fill the list with. Finally, we use the addAll
method from the Collections
class to add all elements from elementsToAdd
to list
. This allows us to quickly fill the list
with the desired elements.
Note that we use the toArray
method to convert the elementsToAdd
list to an array, which is required by the addAll
method. The new String[0]
argument specifies that we want to create a new array of type String
with a length of 0, and the toArray
method will automatically resize the array as needed.
When you run this code, it will output:
[Element 1, Element 2, Element 3]
This demonstrates how you can quickly fill a list in Java using the addAll
method.