This example shows you how we can sort items of an ArrayList using the Collections.sort() method. Beside accepting the list object to be sorted we can also pass a Comparator implementation to define the sorting behaviour such as sorting in descending or ascending order.
package org.kodejava.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
public class ArrayListSortExample {
public static void main(String[] args) {
/*
* Create a collections of colours
*/
List<String> colours = new ArrayList<>();
colours.add("red");
colours.add("green");
colours.add("blue");
colours.add("yellow");
colours.add("cyan");
colours.add("white");
colours.add("black");
/*
* We can sort items of a list using the Collections.sort() method.
* We can also reverse the order of the sorting by passing the
* Collections.reverseOrder() comparator.
*/
Collections.sort(colours);
System.out.println(Arrays.toString(colours.toArray()));
colours.sort(Collections.reverseOrder());
System.out.println(Arrays.toString(colours.toArray()));
}
}
The code will output:
[black, blue, cyan, green, red, white, yellow]
[yellow, white, red, green, cyan, blue, black]
Founder at Kode Java Org
A programmer, recreational runner and diver, live in the island of Bali, Indonesia. Programming in Java, Spring, Hibernate / JPA. You can support me working on this project, buy me a cup of coffee ☕ every little bit helps, thank you 🙏
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