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PlatFormCloud Clone and DeepClone
Hi Experts,
What is the difference between Clone () and DeepClone() in Apex? When should we use what? Can someone explain with an example?
Thanks!
What is the difference between Clone () and DeepClone() in Apex? When should we use what? Can someone explain with an example?
Thanks!
Here is a Small Example to Understand difference between them:
I am just inserting a New Account with some fields. This creates a record in the Account as shown below:
Now, I am cloning it and inserting again. It creates a new copy of the record with same values, since it keeps the reference, new record ID is generated for cloned record.
Now, when I try to deepclone the record:
(Deepclone is done by keeping tru in the parameters: Syntax - clone(preserveId, isDeepClone, preserveReadonlyTimestamps, preserveAutonumber)) It shows an error, because the Id is also considered and cannot insert the deppcloned record:
Best Regards,
BALAJI
All Answers
Basic difference between clone and deep clone are follows :
Clone:
- Generally clone the list of object and keep the reference.
- Supports primitive data type
- Parameters are not applicable.
Deep clone:- Generally it clone the list of object but don't hold any reference.
- doesn't support primitive datatype.
- Parameter are applicable.
Please find below links for more uderstanding:http://www.infallibletechie.com/2014/08/difference-between-clone-and-deepclone.html
https://developer.salesforce.com/forums/?id=906F0000000BH0gIAG
Let us know if that helps you.
Best Regards,
BALAJI
Can you please explain when should I use clone and when DeepClone?
Clone: means creating a new record with the existing details of another reord.
Here is the example:
Account acc = [SELECT Name, Type FROM Account LIMIT 1];
Account accCopy = acc.clone(false, false, false, false);
if you insert accCopy, it will be the exact copy of acc.
DeepClone: creating a new record with the existing details of another reord along with related lists.
Thank You.
http://blog.jeffdouglas.com/2009/11/19/apex-deep-clone-controller/
Please mark it as best answer if it is hepled you.
Thank You.
Here is a Small Example to Understand difference between them:
I am just inserting a New Account with some fields. This creates a record in the Account as shown below:
Now, I am cloning it and inserting again. It creates a new copy of the record with same values, since it keeps the reference, new record ID is generated for cloned record.
Now, when I try to deepclone the record:
(Deepclone is done by keeping tru in the parameters: Syntax - clone(preserveId, isDeepClone, preserveReadonlyTimestamps, preserveAutonumber)) It shows an error, because the Id is also considered and cannot insert the deppcloned record:
Best Regards,
BALAJI
The "clone" method documentation should describe how just the "root object" is cloned (the object on which clone is called), whilst nested/referenced objects are maintained by reference (and not copied by value), whether these are SObjects or other Apex objects.
For example, cloning a Map<String, List<String>> will create a new map with new map entries but the same keys and values; each value (a list) is shared between the maps. Since lists are mutable this is problematic; updating a list from one map will update it in the other map (since it is shared).
Unfortunately, deepClone cannot be used with anything that isn't SObject based. The cloner code must do more. Continuing this example, the values can be cloned too via:
for (String key : myMap.keySet()) {
myMap.put(key, myMap.get(key).clone());
}
Since String instances are immutable there is no harm sharing these between maps/lists/sets/objects.
Such an example really should appear in the documentation.
I tried to implement a clone() method on one of my Apex classes, and it told me the method already exists. Took me forever to figure out that's because it comes from the base Object class that all Apex classes inherit from. I kept thinking I had somehow created it accidentally.
The Object base class is the best-kept secret in Apex. I've never found any official documentation about it, and the un-official documentation I've found says it only has 2 methods: hashcode() and equals(object). Guess we can add a third now. (Oh, and if you're thinking of using the 'override' keyword for your own clone() method, don't bother. The one inherited from Object can't be overridden, and you will get the error: "@override specified for non-overriding method".)
I will have to use deepclone() for my method, though that's not an intuitive name for those not already familiar with the concept. Wish I knew what purpose a clone() method serves on a root class like Object. With no knowledge of the structure of any child class (which for a root class is ALL the classes) it could only make the absolute shallowest of copies. So why have it at all?
global class /*System.*/Object { global virtual Boolean equals(Object obj) {...} global virtual Integer hashCode() {...} global virtual String toString() {...} } }The fact that there is a clone method hidden in there implies, to me, one of two things:It obviously is just copying the block of memory directly - no other implementation would work so universally - and I can see why that's not code you'd want to cut/paste individually into all your child classes. But there had to be a way to give themselves access to the Java super class method (to do the hard work) without making a public, non-virtual Apex method that basically locks the rest of us out of using that signature in Every. Other. Class. (I'm thinking something like VS's internal scope keyword. Or just, y'know, add the virtual keyword to it in the Apex Object.)
Eh, whatev's - no sense crying over what can't be helped, as grandma always said. Incidentally, what IDE are you using? A good alternative to the somewhat clunky Developer Console would be much appreciated.