im trying to find biggest negative number in array c#

Question

Running perfect but there is no result only cursor. The expected result is -15

        int[] dizi = { 4, 5, -15, 22, -34, 3, 0, 7, 43, 100 };
        int maxNumber = 0;

        for (int i = 0; i < dizi.Length; i++)
        {
            if (dizi[i] < 0)
            {
                if (maxNumber < dizi[i])
                {
                    maxNumber = dizi[i];
                    Console.WriteLine(maxNumber);
                }
            }
        }
        Console.ReadKey();

`if (maxNumber < dizi[i])` If maxNumber is 0, it will never be smaller than a negative number. — Dennis_E, Sep 14 '16 at 12:17
Use a debugger. Go through it line by line. You'll notice what @Dennis_E said to be the problem. — Sami Kuhmonen, Sep 14 '16 at 12:19
I Second what Sami says: If you want to really learn what is wrong with it, single-step through it in the debugger. There's no better way to understand your code. — Matthew Watson, Sep 14 '16 at 12:26

Farhad Jabiyev · Answer 1 · 2016-09-14T12:33:32.623

7

You can use Where and Max extension methods from System.Linq namespace:

var maxNegative = dizi.Where(x => x < 0).Max(); 
Console.WriteLine(maxNegative);

Max() will throw exception if there is not any negative number in the collection. So, you may want to use DefaultIfEmpty if you want to return 0 instead of any exception:

var maxNegative = dizi.Where(x => x < 0)
        .DefaultIfEmpty()
        .Max();

edited Sep 14 '16 at 12:33

answered Sep 14 '16 at 12:15

Farhad Jabiyev

26,014
8
72
98

@AnektarcıLegend Actually, this is not a big deal. But, of course it might be better to write your own code in the beginning rather than using Linq methods – Farhad Jabiyev Sep 14 '16 at 12:39
1

+1 for `.DefaultIfEmpty()` mentioning. Extreme cases (no negative numbers in this particular code) are worth considering. – Dmitry Bychenko Sep 14 '16 at 12:42

fubo · Answer 2 · 2016-09-15T05:53:16.870

3

Use Max() to determine your desired value

int[] dizi = { 4, 5, -15, 22, -34, 3, 0, 7, 43, 100 };
int result = dizi.Where(x => x < 0).Max();

If you want to keep your code, replace int maxNumber = 0; with int maxNumber = int.MinValue; so maxNumber gets overwritten, otherwise there can't be a bigger negative number compared to 0

edited Sep 15 '16 at 05:53

answered Sep 14 '16 at 12:16

fubo

44,811
17
103
137

the question is vague defined so i assume there are negative numbers – fubo Sep 14 '16 at 12:18

Rahul Tripathi · Answer 3 · 2016-09-14T12:32:38.900

0

You can try this:

int maxNumber = 0;
    for (int i = 0; i < dizi.length; i++) {
        if (dizi[i] < 0) {
            if (maxNumber == 0 || dizi[i] > maxNumber ) {
                maxNumber = dizi[i];
            }
        }
    }
return maxNumber;

IDEONE DEMO

edited Sep 14 '16 at 12:32

answered Sep 14 '16 at 12:20

Rahul Tripathi

168,305
31
280
331

1

thx @Rahul Tripathi once i add 'maxNumber == 0 ||' i get right result – Anektarcı Legend Sep 14 '16 at 12:27

score 0 · Answer 4 · answered Sep 14 '16 at 12:46

If you are looking for non-Linq solution (good old loop):

    int[] dizi = { 4, 5, -15, 22, -34, 3, 0, 7, 43, 100 };
    int maxNumber = 0;

    foreach (var item in dizi)
      if ((item < 0) && (maxNumber == 0 || item > maxNumber))
        maxNumber = item;

    Console.WriteLine(maxNumber);
    Console.ReadKey();

This code either prints out the maximum negative number -15 or 0 if the coolection (dizi) doesn't contain any negative numbers

score 0 · Answer 5 · answered Sep 14 '16 at 13:06

0

i realize if maxNumber lower than any array elements for example int maxNumber=-100 program works too

answered Sep 14 '16 at 13:06

Anektarcı Legend

21
1

score 0 · Answer 6 · answered Sep 14 '16 at 13:08

Replace your code with this and you will get the correct output

   max=0;
   while(i<dizi.Length)
   {
      if(dizi[i]<max)
       max=dizi[i];
      i++;
   }
   if(max!=0)
   {
      Console.WriteLine(max);
   }
   else Console.WriteLine("No negative number")
 }

im trying to find biggest negative number in array c#

6 Answers6