CODEWITHSUNDEEP
java
Trần Văn Thành
Trần Văn Thành

Reputation: 9

which one is more efficient use clone or use constructor and assign

i have a linkedlist and i want to make a copy of that linkedlist. does clone run faster than create new instance and then assign value for it ? for example i have

LinkedList<MyClass> list = new LinkedList<MyClass>();
list.add(instance1);
list.add(instance2);

Use clone:

LinkedList<MyClass> list2 = list.clone();

Use constructor:

LinkedList<MyClass> list2 = new LinkedList<MyClass>();
   for(MyClass myclass : list){
   list2.add(myclass);
}

Upvotes: 1

Views: 44

Answers (1)

Suresh Atta
Suresh Atta

Reputation: 121998

Best is use the shallow copy constructor. You wrote Use constructor and not using. You are looping on it.

Among all I would suggest to use 

List<MyClass> list2 = new LinkedList<MyClass>(list);

Even Josh Bloch suggest the same

The truth of the matter is that you don't provide any capability to your clients by implementing Cloneable and providing a public clone method other than the ability to copy. This is no better than what you get if you provide a copy operation with a different name and you don't implement Cloneable. That's basically what you're doing with a copy constructor. The copy constructor approach has several advantages, which I discuss in the book. One big advantage is that the copy can be made to have a different representation from the original. For example, you can copy a LinkedList into an ArrayList.

Upvotes: 2

Related Questions