Overriding toString()

Core exercise

Add toString() to Personne (it must return "Jean Dupont (18 ans)", “ans” being French for “years old”) and override it in Etudiant to add the number: "Jean Dupont (18 ans) - 3iL2025". Then check that System.out.println(personne) directly prints the right text.

A workshop goes here: you write and run code in it. It requires JavaScript.

Starting code

Personne.java

public class Personne {

    private String nom;
    private String prenom;
    private int age;

    public Personne(String nom, String prenom, int age) {
        this.nom = nom;
        this.prenom = prenom;
        this.age = age;
    }

    public String getNom() {
        return nom;
    }

    public String getPrenom() {
        return prenom;
    }

    public int getAge() {
        return age;
    }

    // TODO : @Override public String toString() -> "Jean Dupont (18 ans)"
}

Etudiant.java

public class Etudiant extends Personne {

    private String numEtudiant;

    public Etudiant(String nom, String prenom, int age, String numEtudiant) {
        super(nom, prenom, age);
        this.numEtudiant = numEtudiant;
    }

    public String getNumEtudiant() {
        return numEtudiant;
    }

    // TODO : @Override public String toString() avec super.toString() + " - " + numEtudiant
}

Exercices.java

public class Exercices {

    public static void main(String[] args) {
        System.out.println(new Personne("Dupont", "Jean", 18));
        System.out.println(new Etudiant("Dupont", "Jean", 18, "3iL2025"));
    }
}

The core exercise is validated in the workshop, which requires JavaScript.

Hint 1

toString() is called automatically as soon as an object is concatenated or printed. In Etudiant, reuse the parent’s work with super.toString() instead of rewriting everything. The @Override annotation asks the compiler to check that you are indeed overriding an existing method.