NSMutableArray - Add array at start

Question

It is a simple pull to refresh case. I have data loaded into table and have a mutable data array at back-end, I receive a array of new data and want to add this complete array a

Answer 1

Creating a new array is probably your best solution, but you can also use a loop

NSUInteger index;

index = 0;
for ( id item in sourceArray )
{
    [destArray insertObject:item atIndex:index];
    index++;
}

Answer 2

Just simple way:

NSMutableArray *arrayTmp = [firstArr addObjectsFromArray:myArray];
myArray = arrayTmp;

Answer 3

First, build an NSIndexSet.

NSIndexSet *indexes = [NSIndexSet indexSetWithIndexesInRange:
    NSMakeRange(0,[newArray count])];

Now, make use of NSMutableArray's insertObjects:atIndexes:.

[oldArray insertObjects:newArray atIndexes:indexes];

---

Alternatively, there's this approach:

oldArray = [[newArray arrayByAddingObjectsFromArray:oldArray] mutableCopy];

Answer 4

-insertObject:atIndexes: is easy enough, and should (I believe) be more efficient than using -addObjects and swapping arrays. It'd probably end up looking something like this:

[existingResults addObjects:newResults atIndexes:[NSIndexSet indexSetWithIndexesInRange:NSMakeRange(0, newResults.count)]]`

Answer 5

NSMutableArray offers the insertObjects:atIndexes: method, but it's easier to append the way you suggest using addObjectsFromArray:.