ios add array to array in front

Question

I have an existing array to which i want to add an other array in the front of the existing array.

Add to the end is no problem with

[existingArray addObjectsFromArray:newArray];

But how to add it to the front?

Kurt Revis · Accepted Answer · 2012-04-20 07:28:54Z

19

You can do this without a temporary array, and without assuming that newArray is an NSMutableArray, and without making an NSIndexSet:

[existingArray replaceObjectsInRange:NSMakeRange(0,0)
                withObjectsFromArray:newArray];

answered Apr 20, 2012 at 7:28

Kurt Revis

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1 Comment

Zoltán Over a year ago

Nice and elegant solution.

McGarnagle · Accepted Answer · 2012-04-21 09:05:13Z

16

Same method, but invert the order and re-assign:

[newArray addObjectsFromArray:existingArray];
existingArray = newArray;

edited Apr 21, 2012 at 9:05

McGarnagle

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answered Apr 20, 2012 at 7:23

mobius

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Comments

Nitin · Accepted Answer · 2012-04-20 07:23:00Z

3

 [newArray addObjectsFromArray:existingArray];
 existingArray = newArray;

Hope,this will help you..enjoy...

answered Apr 20, 2012 at 7:23

Nitin

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Comments

Antonio MG · Accepted Answer · 2012-04-20 07:23:49Z

2

You can create a 3rd array and add the elements in the order you want, then asing it back to the first one:

NSMutableArray *tempArray = [NSMutableArray arrayWithArray:newArray];
[tempArray addObjectsFromArray:existingArray];

answered Apr 20, 2012 at 7:23

Antonio MG

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Comments

Costique · Accepted Answer · 2012-04-20 07:29:07Z

2

For completeness' sake here's a very different way:

NSIndexSet *indexes = [NSIndexSet indexSetWithIndexesInRange: (NSRange) {0, [newArray count]}];
[existingArray insertObjects: newArray atIndexes: indexes];

answered Apr 20, 2012 at 7:29

Costique

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Comments

Dinesh · Accepted Answer · 2012-04-20 07:26:15Z

0

You can try add objects to index below code:

[existingArray insertObjects:newArray atIndexes:0];

Thanks..!

answered Apr 20, 2012 at 7:26

Dinesh

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1 Comment

Dmitry Nelepov Over a year ago

U will get error [NSMutableArray insertObjects:atIndexes:]: index set cannot be nil

Kai Huppmann · Accepted Answer · 2012-04-20 07:26:43Z

0

Think the two first answers are more elegant, but here's another way:

Use:

[existingArray insertObjects:newArray atIndexes:indexSet];

where the indexSet runs from 0 to newArray.count-1 .

answered Apr 20, 2012 at 7:26

Kai Huppmann

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Comments

Ranga · Accepted Answer · 2012-04-20 07:25:55Z

-2

To insert jjust before the existing array u must use index 0

[newArray insertObject: existingArray atIndex:0]

answered Apr 20, 2012 at 7:25

Ranga

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1 Comment

user2387149 Over a year ago

that whole insert the whole array at index 0

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