OC -- NSDictionary NSMutableDictionary

NSDictionary  NSMutableDictionary 只能存放OC对象，不能存放int, float, double, struct, enum类型数据

NSDictionary *dict1 = @{@"name" : @"As god name", @"address" : @"shanghai", @"program" : @"ios"};

NSDictionary *dict2 = [NSDictionary dictionaryWithObjectsAndKeys:@"name" : @"xingxing", @"address" : @"universe", @"program" : @"unix", nil];  // 不常用

NSMutableDictionary *dict3 = @{@"name" : @"cnblog", @"address" : @"Internet", @"program" : @"ios"};

NSMutableDictionary *dict4 = [NSDictionary dictionaryWithObjectsAndKeys:@"name" : @"hero", @"address" : @"china", @"program" : @"oc", nil];  // 不常用

[dict3 setObject:@"like" forKey:@"run"];  // 添加键值对

[dict3 removeObjectForKey:@"program"];  // 删除键值对

NSUInteger *count = dict3.count;  // 取出dict3中键值对的总数

NSString *str1 = dict3[@"name"];

NSDictionary  NSMutableDictionary 的遍历

[dict3 enumerateKeysAndObjectsUsingBlock:

^(id key, id obj, BOOL *stop){

　　NSLog(@"%@ --- %@", key, obj);

}

];