Java : object of a class as instance variable in same class

Question

作为初学者，我有一个概念上的疑问。类类型对象作为同一个类中的成员/实例变量有什么用？像这样:

class MyClass {

static MyClass ref;
String[] arguments;

public static void main(String[] args) {
    ref = new MyClass();
    ref.func(args);
}

public void func(String[] args) {
    ref.arguments = args;
}

提前致谢!

Answer 1

这用于 singleton pattern :

class MyClass {
    private static final MyClass INSTANCE = new MyClass();
    private MyClass() {}
    public static MyClass getInstance() {
        return INSTANCE;
    }
    // instance methods omitted
}