Arraylist question

[stuckonjava]

for the add(i,e) method in an ArrayList it states:

insert a new element e into S to have index i; an error condition occurs if i < 0 or i > size();

Could someone explain to me what is wrong with having i >size()?

thanks

[JosAH]

for the add(i,e) method in an ArrayList it states:

insert a new element e into S to have index i; an error condition occurs if i < 0 or i > size();

Could someone explain to me what is wrong with having i >size()?

thanks

Suppose your ArrayList has ten elements in it; so its size == 10; also suppose that you want to add something at position 100; 100 > 10 and what are the other ninety elements supposed to be?

kind regards,

Jos

[stuckonjava]

Suppose your ArrayList has ten elements in it; so its size == 10; also suppose that you want to add something at position 100; 100 > 10 and what are the other ninety elements supposed to be?

kind regards,

Jos

Is there not allowed to be a gap in between? if not why not? Thanks

[quad64bit]

Is there not allowed to be a gap in between? if not why not? Thanks

Not if you're trying to access them by index!

If you have 10 elements spread across 100 indexes, what is the size of the array?
10
But what is the highest index?
99

So, if you iterate from 0 to 9, you get any elements in those indexes, but what about the ones at indexes 10-99?

[JosAH]

Is there not allowed to be a gap in between? if not why not? Thanks

You can mimic that behaviour wth a Map<Integer, T>

kind regards,

Jos

[CostaInf]

Salut a tous le monde, j'ai essayer de faire un petit code java, (je suis débutant) pour manipuler des ressources (Enseignants et Enseignement) la première classe Enseignant (j'ai travailler avec ArrayList) comme suit:

import java.util.ArrayList;
public class Enseignant {
private String NomEn;
private String NiveauEn;
private String idEnseign;


public Enseignant(String idEn,String Nom , String Niveau ){
// TODO Auto-generated constructor stub
this.idEnseign = idEn;
this.NomEn = Nom;
this.NiveauEn = Niveau;
}

public void setNom(String nom) {
this.NomEn = nom;
}
public String getNom() {
return NomEn;
}

public void setId(String Id) {
this.idEnseign = Id;
}
public String getId() {
return idEnseign;
}

public void setNiveau(String Niveau) {
this.NiveauEn = Niveau;
}
public String getNiveau() {
return NiveauEn;
}

public String toString() {
return "Enseignant [ Id : " + idEnseign+" Nom : " + NomEn + " Prénom : " + PrenomEn + " Niveau : "+NiveauEn+"]\n";
}

et la classe Enseignement aussi comme celle là! ArrayList, en changeant que les attributs (IntituleModule, Unite çàd(le module est appartient à une unité fondamentale ou secondaire)
et le problème qui se pose, je veux connaitre si je peux élaborer une List des Lists(ArrayList d'ArrayList): dans la classe ressources j'ai développer cette méthode qui permet d'ajouter une ressources(Enseignant ou bien Enseignement) :

public static void AddRess(String D,ArrayList<Enseignant> E,ArrayList<Enseignement> EM, ArrayList<Classe> C, ArrayList<Salle> S){

final Ressources RSS = new Ressources(D,E,EM,);
R.add(RSS);
}
public static void main(String[] args) {
// TODO Auto-generated method stu
EnsModels E = new EnsModels();
EnsmModels Em=new EnsmModels();

ENS = E.getEns();
ENSM = Em.getEnsm();

ArrayList<Ressources> R = new ArrayList<Ressources>();

AddRess(DEP,ENS, ENSM);

System.out.println("Ressources Humaines!");
System.out.print(R);

quelqu'un me donner un un coup de main! S.V.P , et merci tout d'abord !

[pbrockway2]

Hi CostaInf, welcome to the forums!

Please start a new thread for your question rather than adding it on to this one. (You will probably get the most responses if you post in English if you can.)