Objective-C中NSNumber与NSDictionary的用法简介

void number() {      // 将int类型的10 包装成 一个NSNumber对象      NSNumber *number = [NSNumber numberWithInt:10];      NSLog(@"number=%@", number);            NSMutableArray *array = [NSMutableArray array];      // 添加数值到数组中      [array addObject:number];            // 取出来还是一个NSNumber对象，不支持自动解包(也就是不会自动转化为int类型)      NSNumber *number1 = [array lastObject];            // 将NSNumber转化成int类型      int num = [number1 intValue];      NSLog(@"num=%i", num);  } 

NSArray * skyAArrays = [NSArray arrayWithObjects:@"A天空1号",@"A天空2号",@"A天空3号",nil];     NSArray * skyBArrays = [NSArray arrayWithObjects:@"B天空1号",@"B天空2号",@"B天空3号",nil];     NSArray * skyCArrays = [NSArray arrayWithObjects:@"C天空1号",@"C天空2号",@"C天空3号",nil];         // NSArray * skyArray = [NSArray arrayWithObjects:skyAArrays,skyBArrays,skyCArrays, nil];        //字典中所有的key     NSArray * keys = [NSArray arrayWithObjects:@"name",@"sex",@"age",nil];    //字典中所有跟key对应的value     NSArray * values = [NSArray arrayWithObjects:@"liuhui",@"男",[NSNumbernumberWithInt:36],nil];    //创建字典对象方法1     NSDictionary * myDic = [[NSDictionary alloc]initWithObjects:values forKeys:keys];     NSLog(@"my dic = %@",myDic);    // 创建字典对象方法2         NSDictionary * yourDic = [[NSDictionary alloc] initWithObjectsAndKeys:skyAArrays,@"A",skyBArrays,@"B",skyCArrays,@"C",nil];     NSLog(@"your dic = %@",yourDic);          NSLog(@"%@",[yourDic objectForKey:@"A"]);     // - (NSArray *)allKeys; 返回的是 NSArray类型,方便用 objectAtIndex取出一个个key     NSLog(@"%@",[yourDic allKeys]);     NSLog(@"%@",[yourDic allValues]);        //添加数据(setObject 一般没有一种key才添加,有同名的key而用这种方法,会覆盖掉)，注意：id key  是成对出现的      [mutableDictionary setObject:@"Good lucky"forKey:@"why"];      [mutableDictionary setObject:@"bye bye" forKey:@"how"]; 

   //删除指定键值的数据      [mutableDictionary removeObjectForKey:..];     //删除所有数据      [mutableDictionary removeAllObjects]; 

    //字典的普通遍历(无序)     for (int i =0; i < [yourDic count]; i++) {             NSLog(@"key = value <====> %@ = %@",[[yourDic allKeys] objectAtIndex:i],[yourDic objectForKey:[[yourDic allKeys]objectAtIndex:i]]);     }         // 字典的快速遍历 取出来的obj一定是key     for (id obj in yourDic) {            NSLog(@"%@",obj);         id value = [yourDic objectForKey:obj];           NSLog(@"%@",value);     }