I have the following ArrayList<Integer> :
ArrayList<Integer> sequencia = new ArrayList<>();
sequencia.add(2);
sequencia.add(11);
sequencia.add(12);
sequencia.add(13);
sequencia.add(14);
sequencia.add(14);
System.out.println(sequencia.toString());
It returns this:
[2, 11, 12, 13, 14, 14]
But I want it to look like this:
[2, 11, 12, 13, 14]
I want to either delete the repeated ones or group the values.
Use streams to filter :
import java.util.*;
import java.util.stream.Collectors;
public class Program {
public static void main (String[] args) {
ArrayList<Integer> sequencia = new ArrayList<>();
sequencia.add(2);
sequencia.add(11);
sequencia.add(12);
sequencia.add(13);
sequencia.add(14);
sequencia.add(14);
System.out.println(sequencia.stream().distinct().collect(Collectors.toList()).toString());
}
}
See running on ideone . And in Coding Ground . Also I put it in GitHub for future reference .
You have a more "manual" solution that works on versions before Java 8. I do not like these HashSet , although internally it is likely that distinct() will use it, but at least it's an implementation detail.
The simplest way is to use an implementation of the Set interface. More precisely a java.util.TreeSet .
For example:
Set<Integer> semDuplicidade = new TreeSet<>(sequencia); // sua lista