Rec 05

Problems

01. Stack and Heap with nested class

1. In the Static nested class, this is as long as it is used in a non-static method.

2. When accessing the captured variables, don't need any this or what.

3. Variable capture will also capture the instance that invokes the method where the local class comes from.

For example, the stack frame at Line A for the following code is as follows,

class B {
    int x = 1;
    void f() {
        int y = 2;
        class A {
            void g() {
                B.this.x = y; // <--
            }
        }
        A a = new A();
        // Line A
        a.g();
    }
}

02. Write an immutable class

1. Make fields/class final

2. The class which extends from the immutable class may not be an immutable class.

Tips

1. Make fields/class final

2. The class which extends from the immutable class may not be an immutable class.

3. In the Static nested class, this is as long as it is used in a non-static method.

4. When accessing the captured variables, don't need any this or what.

5. Variable capture will also capture the instance that invokes the method where the local class comes from.