在Objective-C中创建二维数组

// 使用NSArray创建二维数组
NSArray *array1 = @[@[@1, @2, @3], @[@4, @5, @6], @[@7, @8, @9]];

// 使用NSMutableArray创建二维数组
NSMutableArray *array2 = [NSMutableArray arrayWithObjects:
                           [NSMutableArray arrayWithObjects:@1, @2, @3, nil],
                           [NSMutableArray arrayWithObjects:@4, @5, @6, nil],
                           [NSMutableArray arrayWithObjects:@7, @8, @9, nil],
                           nil];