CODEWITHSUNDEEP
javalistreplace
user471450
user471450

Reputation:

java replace list with sublist

I have a list 

ArrayList list = new ArrayList(Arrays.asList(1,2,3,4,5,3,4,2,4,5,3,10));

And I have another sublist 

ArrayList sublist = new ArrayList(Arrays.asList(4,5,3));

I was looking around for a functionality to replace the sublist inside list

with another sublist

ArrayList sublist = new ArrayList(Arrays.asList(100,100)));

so after the find and replace , the new list should become :

list = (1,2,3,100,100,4,2,100,100,10);

I could not find any api for this one in java.

Upvotes: 0

Views: 2332

Answers (2)

Matt Ball
Matt Ball

Reputation: 359776

If you create the sublist as a true sublist of list, e.g. using List#subList(), then (non-structural) changes made to sublist will be reflected in list.

List<Integer> list = Lists.newArrayList(1, 2, 3, 4, 5, 3, 4, 2, 4, 5, 3, 10);
List<Integer> sublist = list.subList(3, 6);

for (int i=0; i<sublist.size(); i++)
{
    sublist.set(i, 100);
}

System.out.println(sublist);
// prints 100, 100, 100
System.out.println(list);
// prints 1, 2, 3, 100, 100, 100, 4, 2, 4, 5, 3, 10

Demo: http://ideone.com/ljvd0

Lists.newArrayList(...) comes from Google Guava.

Upvotes: 0

pcalcao
pcalcao

Reputation: 15990

Not sure if there exists any api for doing this or not, but what you could do is take advantage of the List interface in Java.

If you combine the use of containsAll(Collection c) Returns true if this list contains all of the elements of the specified collection.

removeAll(Collection c) Removes from this list all of its elements that are contained in the specified collection (optional operation).

and

addAll(int index, Collection c) Inserts all of the elements in the specified collection into this list at the specified position (optional operation).

I think you can easily accomplish what you need.

Take a look here: http://download.oracle.com/javase/6/docs/api/java/util/List.html

Upvotes: 2

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