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It's a bit difficult to implement a deep object copy function. What steps you take to ensure the original object and the cloned one share no reference?
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Copy an Object With Object.assign() was the most popular way to deep copy an object. Object. assign() will copy everything into the new object, including any functions. Mutating the copied object also doesn't affect the original object.
In Deep copy, an object is created by copying data of all variables, and it also allocates similar memory resources with the same value to the object. In order to perform Deep copy, we need to explicitly define the copy constructor and assign dynamic memory as well, if required.
To make a deep copy, use the deepcopy() function of the copy module. In a deep copy, copies are inserted instead of references to objects, so changing one does not change the other.
Deep copy is a process in which the copying process occurs recursively. It means first constructing a new collection object and then recursively populating it with copies of the child objects found in the original. In case of deep copy, a copy of object is copied in other object.
A safe way is to serialize the object, then deserialize. This ensures everything is a brand new reference.
Here's an article about how to do this efficiently.
Caveats: It's possible for classes to override serialization such that new instances are not created, e.g. for singletons. Also this of course doesn't work if your classes aren't Serializable.
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A few people have mentioned using or overriding Object.clone(). Don't do it. Object.clone() has some major problems, and its use is discouraged in most cases. Please see Item 11, from "Effective Java" by Joshua Bloch for a complete answer. I believe you can safely use Object.clone() on primitive type arrays, but apart from that you need to be judicious about properly using and overriding clone.
The schemes that rely on serialization (XML or otherwise) are kludgy.
There is no easy answer here. If you want to deep copy an object you will have to traverse the object graph and copy each child object explicitly via the object's copy constructor or a static factory method that in turn deep copies the child object. Immutables (e.g. Strings) do not need to be copied. As an aside, you should favor immutability for this reason.
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