how to copy the required Items of NSMutableArray to NSArray

Question

I have NSMutableArray of Results it has 6 items. I want to copy the first three contents to another NSArray.

1

did you tried anything ? – Midhun MP Mar 01 '13 at 04:21

score 5 · Accepted Answer · answered Mar 01 '13 at 04:42

5

Just use subarrayWithRange::

NSMutableArray *oldArray = ... // the mutable array with the 6 objects
NSArray *result = [oldArray subarrayWithRange:NSMakeRange(0, MIN(3, oldArray.count))];

answered Mar 01 '13 at 04:42

rmaddy

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wow nice one... never thought of this :) – Anoop Vaidya Mar 01 '13 at 04:46
it is giving exception – Nazia Jan Mar 01 '13 at 05:03
Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[NSMutableArray objectAtIndex:]: index 1 beyond bounds for empty array' – Nazia Jan Mar 01 '13 at 05:03
Did you include the same check I have using `MIN(3, oldArray.count)`? This ensures the code will work even if `oldArray` has less than 3 objects in it. The error indicates that your array is empty. – rmaddy Mar 01 '13 at 05:13
and if i want array items from 3 to 6 then how can i write please – Nazia Jan Mar 01 '13 at 06:16
Just update the values you pass to `NSMakeRange`. But you may need to do more validation of the array count. If you want objects 3 to 6 then make sure the array has at least 6 objects in it first. Just remember that the second argument to `NSMakeRange` is the length, not the end index. – rmaddy Mar 01 '13 at 06:25

Inder Kumar Rathore · Answer 2 · 2013-03-01T04:37:00.460

2

NSMutalbeArray *newArray=[[NSMutableArray alloc] init];
for(int i=0; i < results.count; i++){
    [newArray addObject:results[i]];
    if(i == 2)
       break;
}

edited Mar 01 '13 at 04:37

answered Mar 01 '13 at 04:22

Inder Kumar Rathore

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it gives this exception -[NSMutableArray objectAtIndex:]: index 1 beyond bounds for empty array' – Nazia Jan Mar 01 '13 at 04:31
It means you have only one object – Inder Kumar Rathore Mar 01 '13 at 04:35
i have added my more code of array which is with six items in it check that – Nazia Jan Mar 01 '13 at 05:00

score 2 · Answer 3 · edited Mar 01 '13 at 04:44

2

Try this simple loop:

NSMutableArray *resultantArray=[NSMutableArray new];
for(NSInteger i=0;i<3;i++){
    [resultantArray addObject:firstArray[i]];
}

edited Mar 01 '13 at 04:44

Scott Berrevoets

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answered Mar 01 '13 at 04:32

Anoop Vaidya

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1

@scott: Thanks for that typo correction :) – Anoop Vaidya Mar 01 '13 at 04:44
it is shows incampitibel type of array arguement addObejct 1 – Nazia Jan Mar 01 '13 at 04:59
to make you more clear – Nazia Jan Mar 01 '13 at 05:04
Your `firstArray` or the array from where you are fetching data does not contain 6 objects, i would say it contain less than 3!!! Or check before using this code. check for [arry count] – Anoop Vaidya Mar 01 '13 at 05:06
it shows 6 sir in NSLog – Nazia Jan Mar 01 '13 at 05:06
ObjectData *theCellData = [resultArray objectAtIndex:indexPath.row]; – Nazia Jan Mar 01 '13 at 05:07
this is how access items of the arrays like theCellData.category etc – Nazia Jan Mar 01 '13 at 05:08

how to copy the required Items of NSMutableArray to NSArray

3 Answers3