ios定义数组和字典快捷方式

//标准写法
NSNumber * number = [NSNumber numberWithInt:1];
NSArray * array = [NSArray arrayWithObjects:@"one", @"two", nil];
NSDictionary * dict = [NSDictionary dictionaryWithObjectsAndKeys:@"value1", @"key1", @"value2", @"key2", nil]; 

//快捷写法
NSNumber * number = @1;
NSArray * array = @[@"one", @"two"];
NSDictionary * dict = @{@"key1":@"value1", @"key2":@"value2"}; 

NSMutableArray *m_array = [@[] mutableCopy];
NSMutableDictionary *m_dict = [@{} mutableCopy];