CODEWITHSUNDEEP
objective-cios
SuperString
SuperString

Reputation: 22519

iOS making a 2D array using NSMutable array

I want to make a 2D array like this

[[1,2,3],[94,22],[2,4,6],[1,3,5,6]]

What is the best way to do this for iOS using NSMutable arrays

Upvotes: 1

Views: 7496

Answers (3)

SFeng
SFeng

Reputation: 2276

NSArray *array = @[@[@1, @2, @3],
                   @[@94, @22],
                   @[@2, @4, @6],
                   @[@1, @3, @5, @6]];

NSMutableArray *arrayM = [[NSMutableArray alloc] init];

for(NSArray *nextArray in array)
    arrayM addObject:[[NSMutableArray alloc] initWithArray:nextArray];

Upvotes: 1

Caleb
Caleb

Reputation: 124997

Neither C nor Objective-C truly support 2D arrays. Instead, in either language, you can create an array of arrays. Doing this in C gives you the same effect as a 2D array of ints with 2 rows and 3 columns, or vice versa:

int foo[2][3];

You can do something similar in Objective-C, but since you can't create objects statically, and you can't fix the size of a mutable array, and NSMutableArray holds object pointers rather than ints, it's not exactly the same:

NSMutableArray *foo = [NSMutableArray array];
for (short i = 0; i < 2; i++)
    [foo addObject:[NSMutableArray array]];

Upvotes: 3

Tiki
Tiki

Reputation: 1206

You cannot create a static 2D array with differently sized rows.

Perhaps you can use NSArrays instead of C arrays to achieve this.

edit: This is tedious, but you can try:

NSArray *array1 = [[NSArray alloc] initWithObjects:[NSNumber numberWithInt:2],[NSNumber numberWithInt:1],[NSNumber numberWithInt:3],nil];

And so on for each array, then 

NSMutableArray *mutableArray = [[NSMutableArray alloc] init]; 
[mutableArray addObject:array1];

Upvotes: 5

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