Superclass and subclass constructors use and inherit

Constructors are implicit static methods, and static methods cannot inherit, so constructors cannot inherit;

If another constructor is implemented in the parent class, the parameterless constructor disappears and can no longer be called;

By default, if the parent class constructor is not explicitly called, the default one is called;

When you write a subclass, you must call the parent class constructor (the default call to the parent class without a parameter constructor)

When the parent class has its own constructor (the default parameterless constructor in the parent class disappears), when you write a subclass, you must write your own constructor and call one of the constructors of the parent class in the child constructor to create the parent class , such as super (name), because you want to have subclasses, You have to have a parent class (super () This form of parent constructor can not write, only this one can not write )

If the parent class does not have a constructor written by itself or has a parameterless constructor, in which case the parent class has a parameterless constructor, such as: Parent () {}, where Super () is used in the subclass constructor, or it can be called without writing, because the system will be added by default.

Superclass and subclass constructors use and inherit