Question

I have NSArray1 = (1, 5, 2)
and NSArray2 = (1, 3, 5)

i want to array1 + array2 = (should return) = (2, 8, 7)

(in fact is it even possible to do this with NSArray)?

Heres a similar question
Adding two arrays together
(but this adds the values of the second array onto the end of the first array)

NSArray *a = [NSArray arrayWithObjects: @"1" ,@"2",@"3",nil];
NSArray *b = [NSArray arrayWithObjects: @"1" ,@"2",@"3",nil];
NSMutableArray *c = [[NSMutableArray alloc]init];
c = [a addObjectsFromArray:b];

// just a test code . . . .

Answer 1

If it’s a C array, then just do

int newArray[3];
for (int i=0;i<3;i++)
    newArray[i] = array1[i]+array2[i];

But if it’s a NSArray with NSNumbers (You can’t have primitives in NSArray), then just do

NSMutableArray *newArray = [NSMutableArray array];
for (int i=0;i<[array1 count];i++)
    [newArray addObject:[NSNumber numberWithInt:[[array1 objectAtIndex:i] intValue]+[[array2 objectAtIndex:i] intValue]]];
    //If you're using Mountain Lion, then you can use the following 
    //[newArray addObject:@([array1[i] intValue]+[array2[i] intValue])];

Edit:

If you have more than 1 array, then

int numArrays = 3;
NSArray *arrayOfNum = //An array of arrays that contains all the numbers
NSMutableArray *newArray = [NSMutableArray array]
for (int i=0;i<[array1 count];i++)
{
    int total = 0;
    for (int x=0;x<numArrays;x++)
        total+=[arrayOfNum[x] intValue];
    [newArray addObject:@(total)];
}