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Java class related problems

2022-02-03 01:13:29 【CSDN Q & A】

What is the meaning of the class name as the return value

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The output of this is that students learn

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It is the same as this result
I can't figure out what the meaning of class name as return value is
He is direct new Student Isn't class more labor-saving
Class names are easy to understand as methods , As a return value, I always feel strange
Words , The process of creating objects is just opening up space , Why don't you instantiate when you return a value



Refer to the answer 1：

You this getStudent The overall meaning of the method is 

//  Create a return Student Object method public StudentgetStudent(）{        //  Create a Student object s        Student s=new Student(）        //  Return to new object s        return s}


Refer to the answer 2：


Refer to the answer 3：

It depends on the specific scene
This really doesn't make any more sense in your code
If you write like this , You can make sure you get the same... Every time Student

public Teacher{    Student student = null;    public Student getStudent(){        if (student == null){            student = new Student();        }        return student;    }}


Refer to the answer 4：


Refer to the answer 5：

Take a scene , Generally, this return type is an interface ,Teacher What is returned is the implementation class of this interface , As for what is written in this implementation class, you don't have to worry about , You just call it according to the method provided by the interface , polymorphic .
Programming is a multi-party project , When you call a third party provided sdk Or interface , You don't need to focus on how others achieve , Just bring it here .



Refer to the answer 6：


Refer to the answer 7：

This is an exercise , I'm teaching you how to treat a class as a parameter or return value
Just like you learn math in primary school , It must be from 1+1 Start learning
You can't feel like learning 1+1 It's no use



Refer to the answer 8：

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