- When students understand that a child class can call methods and constructors from their parent class they sometimes incorrectly conclude that constructors are also inherited.
- For example students may understand the following code:
public class TheParentClass {
String myName;
public void parentMethod(){
this.myName = "bob";
}
}
public class TheChildClass extends TheParentClass {
public static void main(String[] args) {
TheChildClass obj = new TheChildClass();
obj.parentMethod(); // Calls parent method!
}
}- However, they may write the following incorrect code, which assumes that the constructor written in
TheParentClassis not inherited. public class TheParentClass {
String myName;
public TheParentClass(String s){
this.myName = s;
}
}
public class TheChildClass extends TheParentClass {
public static void main(String[] args) {
// The following code doesn't compile!
TheChildClass obj = new TheChildClass("alice");
}
}