iOS字母排序、数字排序

  NSMutableArray *_array = [[NSMutableArray alloc] initWithObjects:@"4", @"1", @"10", @"2", nil];

    

    _array = [[NSMutableArray alloc] initWithArray:[_array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

        

//        return [obj1 compare:obj2 options:NSNumericSearch];  //a按照首位排序

        return [obj1 compare:obj2 options:NSForcedOrderingSearch];

        

    }]];

    _array = [[NSMutableArray alloc] initWithArray:[_array sortedArrayUsingSelector:@selector(compare:)]];

    //

    NSMutableArray *_allKeys = [[NSMutableArray alloc]initWithArray:[self.dataDic allKeys]];

    //升序排序

    _allKeys = [[NSMutableArray alloc]initWithArray:[_allKeys sortedArrayUsingSelector:@selector(compare:)]];

    _allKeys = [[NSMutableArray alloc]initWithArray:[_allKeys sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

        return [obj1 compare:obj2 options:NSNumericSearch] == NSOrderedDescending;

    }]];

    NSLog(@"_allKeys%@",_allKeys);

参考文章：http://blog.csdn.net/tetrisos/article/details/7671282

http://hi.baidu.com/ivan_xu/item/5d897c14d51bffe0ddeeca7c

http://code4app.com/snippets/one/排序/521dc6836803fad866000000