objective-c - NSDictionary Objective-C

Question

我正在尝试以字符串作为键以以下方式存储数据，我想要一个数组作为值。

关键对象

“字母”{'a','b','c','d'}
“数字”{1,2,3,4,5,6,7}

在代码中使用 NSDictionary 是否可行？如果是这样，那会是什么样子？我真的很困惑。

Answer 1

一种在代码中执行此操作的简单方法(这只是您可以执行此操作的多种方法之一):

NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setObject:[NSArray arrayWithObjects:@"a", @"b", @"c", @"d", nil] forKey:@"letters"];
[dict setObject:[NSArray arrayWithObjects:[NSNumber numberWithInt:1], [NSNumber numberWithInt:2], [NSNumber numberWithInt:3], [NSNumber numberWithInt:4], nil] forKey:@"numbers"];

它创建了一个 NSDictionary，其中包含一个字符串数组和一个 NSNumber 对象数组，还有其他创建数组的方法，但它演示了一种基本方法.

根据以下评论:

如果您想一次向数组添加项目...

  // create the dictionary and add the letters and numbers mutable arrays
  NSMutableDictionary *dict = [NSMutableDictionary dictionary];
  NSMutableArray *letters = [NSMutableArray array];
  NSMutableArray *numbers = [NSMutableArray array];
  [dict setObject:letters forKey:@"letters"];
  [dict setObject:numbers forKey:@"numbers"];

  // add a letter and add a number
  [[dict objectForKey:@"letters"] addObject:@"a"];
  [[dict objectForKey:@"numbers"] addObject:[NSNumber numberWithInt:1]];  
  // This now has an NSDictionary (hash) with two arrays, one of letters and one 
  // of numbers with the letter 'a' in the letters array and the number 1 in 
  // the numbers array