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Real that variables of primitive types can hold it does not does Indigos or characters not just look

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at the second variety of variables which can hold or object references

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district.

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Create a student object.

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And we saw this exact statement when introducing classes and objects.

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Here s is a variable and it's an object reference and not an object that is it holds bits that reference

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a student object in memory.

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Let's see how this works.

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This statement basically has three parts in it.

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And each of them informs JVM to do something.

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And let's see what those three parts are.

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Here's a fusspot a neat dense GBM to look at space and memory for that reference variable.

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And here is the second part that dolt's GBM took a look at space for a new student object in the memory

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.

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OK so space has been a look at it for reference mailable and space has been and look at it for ex-student

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object in the memory.

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No we need to send a memory address of the student object to that reference variable.

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And for that we have the third part that is an assignment operator assigns a memory address of the student

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object to the variable s.

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So we just mentioned about objects getting stored in memory but that gets stored in especially the memory

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that is assigned to JVM.

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So in JVM starts up it gets a chunk of memory from the underlying operating system in order to run its

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programs and run it off this memory is referred to us heap and all objects are stored on the heap.

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OK so all Java objects get stored on the heap.

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And this diagram shows the heap with all the objects and in our particular example the variable as it

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references one student object on the heap JVM and a non-starter covers heap concept in detail.

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But for now just know that we have a heap and that objects are stored on the heap.

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We looked at big that of all primitives no more object references build dip this GBM specific that is

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big of an object reference on one JVM maybe smaller or larger than that of an object reference on another

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JVM holloed on a given JVM.

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All of the references will have the same Babet regardless of the objects they reference different value

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for an object reference is null non-employees the object reference is not pointing to anything.

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So in this statement S.M. be assigned a different null until it is explicitly initialized.

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Now if you use a dot operator on a null reference that will lead to an exception called null pointer

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exception exceptions would be covered later in a separate chapter called exceptions.

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And that's about it.

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That's the I know for discussion on object references.

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Thank you