理解和掌握类的加载过程以及子类继承父类后，重写方法的调用问题

public class Base {

private String baseName = "base";

public Base() {
callName();
}

public void callName() {
System.out.println(baseName);
}
}

public class Child extends Base {

private String baseName = "sub";

public void callName() {
System.out.println(baseName);
}

public static void main(String[] args) {
Base b = new Child();
System.out.println(b);
}

}