pragma mark - 比较大小

• (void)sortContactIdWith:(NSArray *)idArr{
  NSArray *sortArray = [[NSArray alloc] initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"15",@"12",@"200",@"28",@"200",@"200" ,nil];
  NSNumber * max = [sortArray valueForKeyPath:@"@max.floatValue"];

  NSLog(@"max-------:%@",max);
  }