Serializing object graphs

An object graph is multiple objects that are related to each other either through a direct reference or indirectly through a chain of references.

Serialization is the process of converting a live object graph into a sequence of bytes using a specified format. Deserialization is the reverse process. You would do this to save the current state of a live object so that you can recreate it in the future, for example, saving the current state of a game so that you can continue at the same place tomorrow. Serialized objects are usually stored in a file or database.

There are dozens of formats you can specify, but the two most common ones are eXtensible Markup Language (XML) and JavaScript Object Notation (JSON).

Good Practice: JSON is more compact and is best for web and mobile applications. XML is more verbose but is better supported in more legacy systems. Use JSON to minimize the size of serialized object graphs. JSON is also a good choice...