Copy object at specific index of mutable array to the end of another array

Question

I have a mutable array that has a range of numbers (that are changed dynamically later on if that helps), I grab a random number's index from that array and want to stick it in another array (also mutable). I'm not sure how to grab the object at a certain index and copy it.

Here's what I tried to do:

[btnRange addObject:@"12"];
[btnRange addObject:@"13"];
[btnRange addObject:@"14"];
[btnRange addObject:@"17"];
[btnRange addObject:@"18"];
[btnRange addObject:@"19"];
//start randomising and adding to btnOrder Array

for (NSInteger i=0; i <= 5; i++) {
     id nxt = btnRange[arc4random_uniform([btnRange count])];
     [btnOrder addObject:(@"%@", nxt];
     //[btnOrder addObject[btnRange(nxt)]; --didn't work
     //[btnOrder addObjectsFromArray:(btnRange. nxt]; --didn't work
     //[btnOrder addObject:nxt]; --didn't work (I'm pretty new to this)
}

How can I take the object at a specific index of the first array and copy it over at the end of the second array?

possible duplicate of [Is there some literal dictionary or array syntax in Objective-C?](http://stackoverflow.com/questions/9693647/is-there-some-literal-dictionary-or-array-syntax-in-objective-c) — David Gelhar, Sep 24 '13 at 14:26
Hm, "grab" it with `objectAtIndex:` and "copy" it with `copy` (check the documentation for details) ? — A-Live, Sep 24 '13 at 17:35
I did try that, but `nxt` is an `id` not an integer so it's incompatible to use `objectAtIndex:nxt` because objectAtIndex: requires an int — blindman457, Sep 24 '13 at 23:34

Hitendra Solanki · Answer 1 · 2014-01-31T05:45:32.977

You can get the object from NSMutableArray using [arrayName objectAtIndex:index] 
and add object in NSMutableArray using [arrayName addObejct:object]
[arrayName objectAtIndex:index] return object

[btnRange addObject:@"12"];
            [btnRange addObject:@"13"];
            [btnRange addObject:@"14"];
            [btnRange addObject:@"17"];
            [btnRange addObject:@"18"];
            [btnRange addObject:@"19"];
            //start randomising and adding to btnOrder Array

            for (NSInteger i=0; i <= 5; i++) {
                NSString *nxt = [btnRange objectAtIndex:arc4random()%[btnRange count]];
                [btnOrder addObject:nxt];
            }

score 0 · Accepted Answer · answered Sep 25 '13 at 07:39

I'm not sure how to close this, but the suggested thread had the answer I was looking for!

This was my end code if anyone is interested:

[btnRange addObject:@"12"];
[btnRange addObject:@"13"];
[btnRange addObject:@"14"];
[btnRange addObject:@"17"];
[btnRange addObject:@"18"];
[btnRange addObject:@"19"];
//start ordering
for (NSInteger i=0; i <= 5; i++) {
    id nxt = btnRange[arc4random_uniform([btnRange count])];
    btnOrder[i] = nxt;
    [btnRange removeObject:nxt];
}

Copy object at specific index of mutable array to the end of another array

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