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c'est quoi un constructeur par défaut

package fr.codegym.task.task05.task0522; /* Le maximum de constructeurs */ public class Cercle { public double x; public double y; public double rayon; //écris ton code ici public static void main(String[] args) { } }

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Gellert Varga

niveau Szekesfehervar, Szekesfehervar, Hungary

1 juillet 2021, 13:48

public class Cat {
   public int age;
}

This Cat class contains a default constructor, invisible. Java does it for us. As Thomas said. If you write such a constructor into the Cat class:

public Cat (int age) {
    this.age=age;
}

then the default constructor from JVM no longer exists, only this new one. In this case we have to write the default constructor separately if we need it:

public class Cat {
   public int age;

   public Cat (int age) {
     this.age=age;
   }

   public Cat() {   // default constructor (no-argument)
   }
}

Thomas

niveau Bayreuth, Bayreuth, Germany

1 juillet 2021, 08:20

It's an automatically (invisibly ) generated no-arg constructor unless you write yourself a constructor. Here CG probably means just a no-arg constructor with that cause they ask you to write constructors.