iOS 数组和字典排序

一、数组排序

数组排序方式1：

 //初始化可变数组
         NSMutableArray *arr1=[NSMutableArray arrayWithObjects:@"giu",@"min",@"Deng",@"liumin", nil];
         //字符串排序
         //创建排序描述符对象NSSortDescriptor，key为空，ascending：升序
         NSSortDescriptor *decri =[NSSortDescriptor sortDescriptorWithKey:nil ascending:YES];
         //定义一个数组，用来盛放排序条件
         NSArray *des =[NSArray arrayWithObject:decri];
         //开始排序
         [arr1 sortUsingDescriptors:des];
         //打印排序内容
         for (int i=; i<arr1.count; i++)
         {
             NSLog(@"arr=%@",[arr1 objectAtIndex:i]);
         }

数组排序方式2：

    NSMutableArray *arr2=[NSMutableArray arrayWithObjects:@"c", @"A",@"z",@"D",nil];

         //区分大小写排序 自带compar方法  选择排序
         [arr2 sortUsingSelector:@selector(compare:)];
         for (int i=; i<arr2.count; i++)
         {
             NSLog(@"arr2=%@",[arr2 objectAtIndex:i]);
         }

二、字典的排序

 //创建5个排序对象
     NSDictionary *dic1 =@{@"price":@"",@"name":@"liu"};
     NSDictionary *dic2 =@{@"price":@"",@"name":@"huang"};
     NSDictionary *dic3 =@{@"price":@"",@"name":@"yoyu"};
     NSDictionary *dic4 =@{@"price":@"",@"name":@"yofu"};
     NSDictionary *dic5 =@{@"price":@"",@"name":@"yosu"};
     //将这些对象放进数组
     NSArray *arr =[NSArray arrayWithObjects:dic1,dic2,dic3,dic4, dic5,nil];
     //调用数组排序方法
     NSArray *arr2 = [arr sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2)
     {
         //取出对象里的一个值作比较，根据大小返回结果
         NSString  *c = [obj1 valueForKey:@"price"];
         NSString  *d = [obj2 valueForKey:@"price"];
         int a =[c intValue]; //转成整形int比较
         int b =[d intValue];
         //按照降序排列，如果升序就返回结果对换
         if (a > b)
         {
             return NSOrderedAscending;
         }else
         {
             return NSOrderedDescending;
         }

     }];
     //循环遍历排序后的字典数组
     for (NSDictionary *dic in arr2)
     {
          NSLog(@"%@",dic);
     }