Deep Copy

Definition of Deep Copy

Deep copy refers to the process of creating a new, independent object as an exact copy or duplicate of an original object, including its data and nested objects. Unlike shallow copy, deep copy duplicates not just the top-level elements but also any referenced objects. This ensures that any changes made to the copied object do not affect the original object and vice versa.


The phonetic pronunciation for the keyword “Deep Copy” is: /diːp ˈkɒpi/Deep: /diːp/Copy: /ˈkɒpi/

Key Takeaways

  1. Deep Copy creates a new object and recursively copies the original object’s elements, including nested objects and collections, to avoid reference sharing.
  2. As Deep Copy duplicates all data, any changes made to either the original or copied object will not affect each other, maintaining data integrity and independence.
  3. Deep Copy can be slower and more memory-consuming compared to Shallow Copy, as it must allocate and store the entire data structure rather than references, so it should be used selectively depending on the use case.

Importance of Deep Copy

The technology term “Deep Copy” is important because it ensures the creation of an independent and self-contained copy of an object, along with all its associated data structures, like nested objects and collections, rather than just replicating the top-level references.

This is crucial in scenarios where modifications to the copied object should not affect the original object, preserving data integrity and avoiding unwanted side effects.

Deep copy thereby enables the safe manipulation or storage of data, enhances security, and ensures the proper functioning of software systems that rely on non-interconnected data copies, making it a vital aspect of programming and data management.


Deep Copy, an essential concept in computer programming, serves a crucial purpose in data manipulation and management by safeguarding the original data structure when duplicating complex objects. This meticulous copying process generates a new, independent object that is entirely separated from the source object, including all nested elements and substructures.

This level of precision allows developers to perform modifications on the copied data without altering the original content of the source object. As a result, they can work on various data manipulations and experiments, such as testing algorithms or simulating scenarios, without the risk of corrupting the original data.

The utilization of Deep Copy is particularly vital in scenarios where data integrity and isolation are paramount, making it an indispensable tool in myriad applications spanning industries like finance, healthcare, and software development. For instance, financial institutions can rely on Deep Copy techniques to simulate multiple investment strategies on cloned market data, eliminating the possibility of tampering with the original dataset.

Healthcare professionals can use Deep Copy to support research initiatives by generating replicas of sensitive patient data. Overall, Deep Copy’s key role in preserving data integrity and fostering secure data manipulation significantly contributes to efficient and reliable outcomes across various sectors.

Examples of Deep Copy

Deep Copy is a technique in programming where a copy of an object or data structure contains the exact values and duplicates of all the references, sub-objects, and elements within the source object. Here are three real-world examples of Deep Copy technology:

Cloning a Graph Data Structure: In graph algorithms, it’s often required to clone the entire graph to protect the original one from unexpected modifications during the computation. Deep Copying comes to the rescue here by replicating the graph with all its nodes, edges, and other properties, so that any changes in the cloned graph do not affect the original one.

Object Serialization and Deserialization: Deep Copy is often used in the process of object serialization and deserialization. When you need to send an object over a network or store it in a file, you can deep copy all the data contained in the object and convert it into a byte stream or another storage-friendly format. Later, the deserialization process restores the object state by deep copying the byte stream back into the original data structures.

Undo/Redo operations in applications: In applications like graphic editors, deep copy is used to maintain a history of user actions. When a user makes a change to an image, the application creates a deep copy of the image before modifying it. If the user wants to undo the change, the application restores the image from the deep copy. This method allows preserving the exact state of the image before and after each editing step, ensuring accurate and reversible changes.

Deep Copy FAQ

1. What is a deep copy?

A deep copy is a process of creating a new object and recursively copying all the values and objects of the original object to the new object. This means that any modification in the new object does not affect the original and vice versa because they both reside in separate memory locations.

2. How is a deep copy different from a shallow copy?

A shallow copy creates a new object and only copies the references of the original object’s properties and methods to the new object. In contrast, deep copy creates a new object and recursively copies all the values and objects of the original object into the new object. Changes in a deeply copied object do not affect the original object, whereas changes to a shallow copied object can affect the original object.

3. When should I use a deep copy?

You should use a deep copy when you need to create a completely independent clone of an object, especially when the object has nested objects or the object properties contain mutable types such as lists, dictionaries, or custom objects. Using a deep copy is beneficial when you want to change the new object’s properties without affecting the original object.

4. How do I create a deep copy in programming languages?

Many programming languages have built-in functions or libraries to create a deep copy, such as Python’s `copy.deepcopy()` function, JavaScript’s `JSON.parse(JSON.stringify(obj))` method, and C#’s `ICloneable` interface. You can also create a custom function to perform a deep copy based on your specific requirements in a programming language.

5. Are there any drawbacks to using deep copy?

While deep copy provides the benefit of creating fully independent objects, it may consume more memory and computational resources, especially if the object to be copied is large or contains a complex structure. This can be a concern if performance and memory efficiency are crucial, as in real-time applications or systems with limited resources.

Related Technology Terms


  • Clone
  • Object Serialization
  • Recursive Copy
  • Independent Copy
  • Reference Copy


Sources for More Information


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