Java Select element of list

Question

I'm stuck at a part when I have to create a list and select something in it.

I have an executable

public class Executable{
    public static void main(String [] args){
        WeekEnd we = new WeekEnd();

        Personne pierre = new Personne("Pierrot");
        Personne anna = new Personne("anna");

        we.addPersonne(pierre);
        we.addPersonne(anna);

        System.out.println("test : "+we.findUsingEnhancedForLoop("anna"));

    }
}

I have my class Personne

public class Personne{
    private String name;

    public Personne(String name){
    this.name=name;
    }

    public String getPersonne(){
    return this.name;
    }
}

And my class WeekEnd where i try to select the name anna

import java.util.List;
import java.util.ArrayList;

public class WeekEnd{
    private ArrayList<Personne> listePersonne;

    public WeekEnd(){
      this.listePersonne = new ArrayList<>();
    }

   public Personne findUsingEnhancedForLoop(
   String name, ArrayList<Personne> listePersonne) {

      for (Personne personne : listePersonne) {
         if (personne.getPersonne().equals(name)) {
              return personne;
         }
     }
     return null;
   }

   public void addPersonne(Personne personne){
      listePersonne.add(personne);
   }
 }

Please, try to give your identifiers in English. How about I ask the question something like this: public void изабериЛичност(. — zlakad
– zlakad, Commented Sep 27, 2018 at 20:07
Under what circumstances may I add “urgent” or other similar phrases to my question, in order to obtain faster answers? — Andreas
– Andreas, Commented Sep 27, 2018 at 20:08
@Andreas that was a just a conclusion with a little joke i can't stay serious too long — Antoine553
– Antoine553, Commented Sep 27, 2018 at 20:11

Mureinik · Accepted Answer · 2018-09-27 20:17:39Z

2

The WeekEnd class already has a listePersonne member. You shouldn't pass such an argument, which will just hide this member:

public Personne findUsingEnhancedForLoop(String name) {
    // Rest of the code, as you had it...

Note, by the way, that using Java 8's streams can clean up the method's implementation considerably:

return
listePersonne.stream().filter(p -> p.getPersonne().equals(name)).findFirst().orElse(null);

answered Sep 27, 2018 at 20:17

Mureinik

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Comments

Mustafa Çil · Accepted Answer · 2018-09-27 20:29:04Z

0

Firstly you shouldn't pass ArrayList<Personne> listePersonne as a parameter in Weekend class. Instead of this you can pass only String name as a parameter.

public Personne findUsingEnhancedForLoop(String name) {

  for (Personne personne : listePersonne) {
     if (personne.getPersonne().equals(name)) {
          return personne;
     }
 }
 return null;
}

Also findUsingEnhancedForLoop method returns a Personne object. If you want to print a Personne's name in System.out.println() you have to override toString() method inPersonne class from Object class.

    @Override
    public String toString() {
        return this.name;
    }

answered Sep 27, 2018 at 20:29

Mustafa Çil

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