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Questions tagged [shallow-copy]

A shallow copy of an object is a duplicate that may not be fully independent of the original, in the sense that any references / pointers it holds to other objects refer to the same objects that the original's do. Use this tag for questions regarding implementing or using shallow copying methods.

Shallow copying is a process by which an object is duplicated to create a copy that may not be wholly independent of the original. Also known as "field by field" copying, this differs from deep copying with respect to the treatment of references / pointers to other objects: shallow copying copies the references / pointers held by the original, whereas deep copying makes a deep copy of each referenced object, too. Shallow copying is "shallow" in the sense that it copies only the original object itself, not any appearing deeper in its reference graph.

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Question about array shallow copy in C#

Just to make sure I'm understanding shallow copies of reference types correctly and that I'm not constructing a huge memory leak here: // Adds text to the beginning of the log RTB // Also keeps the log RTB trimmed to 100 lines var lines = new…
bszom
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Shallow Copying Class Objects vs. String Variables

string a = "John"; string b = "Doe"; a = b; // Shallow copying strings b = "Elon Musk"; Console.WriteLine(a); // Output: Doe This prints "Doe", meaning the change in one variable is NOT reflected to the other variable. However, when "boxing in"…
Emre Bener
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Unexpected values in two-dimensional array

This is probably a duplicate question but I didn't know how to search for it. Can someone explain the bevior from the code snippet to me? I am trying to iterate over a 2-dimensional array, setting each value to the index of the containing row. Yet…
Felix
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Shallow copy in C

This is my first question. I am learning C. And I heard about shallow copy. As I understood, shallow copy means that you copy the address of the object instead of its value. This means that every change to the copied object will affect the original…
Øuss
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Java 8 Streams Shallow copy of map object, cross join using streams

My inputs are : List> = [{1=a, 2=b, 3=c}, {1=d, 2=e, 3=f}] List = [x, y, z] Expected Output is : [ {1=a, 2=b, 3=c, 4=x}, {1=a, 2=b, 3=c, 4=y}, {1=a, 2=b, 3=c, 4=z}, {1=d, 2=e, 3=f,…
NightFury
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JavaScript Spread Operator while making a shallow copy of an array

let arr = [1,2,3] let arr2 = [...arr] let [...arr3] = arr The arr2 and arr3, both make a shallow copy of arr. What is actually the difference?
bbcts
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How do I share elements between ArrayList and TreeSet in Java?

I want to modify the elements of the ArrayList and TreeSet simultaneously. Ex. When I modify an element from the TreeSet, the corresponding element in the Arraylist is modified too.
user799943
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How can I shallow copy a part of list?

I want to shallow copy a part of list, for example: original_list = [0, 1, 2, 3] And I want to copy a part of it list2 = original_list[0:2] list2[0] = 10 wanted output: original_list = [10, 1, 2, 3] But slice only give a new list, Any help would…
Tobiichi
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What happens to Strings when object is cloned in Java?

By default Java does Shallow Cloning, if an object is cloned and it has a String like this String s = new String("Hi"); then the cloned object will point to a new String object or it will have a reference to the previous object? The question here is…
Wilfred Almeida
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How do I use collections in immutable class safely in Java?

I try to implement immutable class, and I see a rule stating "Perform cloning of objects in the getter methods to return a copy rather than the returning actual object reference". I understand that when we use immutables there would be no change in…
coderates
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Issue while making a copy of 2D Array

My target here is to find 'N' for a 2D Array. 'N' = sum of corner elements * sum of non corner elements. For 'N' calculation I change String & Boolean elements to their ASCII, 1 or 0 respectively. But my original array gets altered in this…
thycode2020
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Does the shallow/deep-copy terminology apply for objects without references?

Disclaimer This post is about the correct usage of the terms "shallow-copy" and "deep-copy", specifically when talking about copying an object which does not contain any references. This question is not meant to be (and should not be) opinion-based,…
Felix G
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Is shallow copy implementation different for python list and pandas series?

I know the shallow copy behaviour of list list1 = [1, 2, 3, 4] list2 = copy(list1) # shallow copy of list1 list1 is list2 # False as expected False list1[0] is list2[0] # True as expected True list1[0] = 10 # this will change list1 but not…
cryptomanic
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Cloning a List - how is it done?

I want to make a shallow copy of a List I get returned by a method call (it's public List getScanResults () from Android, see http://developer.android.com/reference/android/net/wifi/WifiManager.html#getScanResults%28%29). The problem is, clone() is…
stefan.at.kotlin
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Deep Copy of object

I have two classes. In one is nested another class. class Person : ICloneable { public string name; public City city; public object Clone() { return this.MemberwiseClone(); } } class City { public string name; …
Rafal
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