如何将2维的整数NSArrays对象添加到Objective-C中的NSMutableArray？

Question

I have a NSMutableArray and want to add a 2 dimensional NSArray with integer parameters to it each time. But after use that values their IDs not show as Integers.And I tried @[i,j] too but it didn't work. Here is my code :

resault = [[NSMutableArray alloc]initWithCapacity:40];

for (int i=0; i<5; i++)
{
   for (int j=0; j<5; j++)
   {
      [resault addObject:@[@(i),@(j)]];
   }
}

Answer 1

Use this code -

NSMutableArray*resault = [[NSMutableArray alloc]initWithCapacity:40];
for (int i=0; i<5; i++)
{
    NSMutableArray*array = [[NSMutableArray alloc]initWithCapacity:40];
    for (int j=0; j<5; j++)
    {
        [array addObject:@[@(i),@(j)]];
    }
    [resault addObject:array];
}

Answer 2

You can try this:

NSMutableArray * ma = [NSMutableArray new];
for (int i = 0; i < 10; i++){
    for (int d = 0; d < 10; d++){
        [ma addObject:[NSString stringWithFormat:@"%i%i",i,d]];
    }
}
NSLog(@"id is %@", ma);

Cycle through the I loop, then the D loop and add into the array as NSString objects. If you need them as NSNumbers, just convert them later. If you are counting up from 0 to n, you can use a single for loop (eg from 0 to 100 would work in the example above), while nesting for loops works better if you're using non numerical IDs.

If you want to keep the 0 character in front of IDs below ten, using a single for loop:

NSMutableArray * ma = [NSMutableArray new];
for (int i = 0; i < 100; i++){

    [ma addObject:[NSString stringWithFormat:@"%02d",i]];
}
NSLog(@"id is %@", ma);

Using your method:

NSMutableArray * ma = [NSMutableArray new];
for (int i = 0; i < 10; i++){
    for (int d = 0; d < 10; d++){
        [ma addObject:@[@(i),@(d)]];
    }
}

int thirtiethI = [ma[30][0] intValue];
int thirtiethD = [ma[30][1] intValue];
NSLog(@"thirtieth: %i %i", thirtiethI, thirtiethD);

Answer 3

resault = [[NSMutableArray alloc]initWithCapacity:40];

for (int i=0; i<5; i++)
{
   for (int j=0; j<5; j++)
   {
       [resault addObject:[NSArray arrayWithObjects:
           [NSNumber numberwithInt:i],
           [NSNumber numberWithInt:j],
           nil]
       ];
   }
}

You can then access the i,j pairs by running through the result array and extracting the stored NSArray and getting the first and second objects sorted therein.

Answer 4

First of all you have to understand the int, float these basic types can not be deposited into the array

So when you add it @(i), this means [NSNumber numberWithInt: i]

The array is the type of NSNumber

If you want to take it out

int result = [resault [30] [0] intValue];