C#中随机交替正负数数组

Question

I would like to generate array of 10 elements with random number between (-10,10).

And scenario is array can contain positive number between (0,10) for odd positions and contain negative number between(-10,0) for even position

For Example : 1,-2,3,-4,7,-1,3,-3,2,-9

And im totally stucked in generating -ve number at even places because im new in programming.

Any Help Is Appreciated,Thanx In Advance

Answer 1

Ok, i got your point. Try This Code

Random rand = new Random();
        int[] arr = new int[10];
        for(int i = 0; i < 10; i++)
        {
            if(i % 2 == 0) 
                arr[i] = rand.Next(1,10);

            else 
                arr[i] = (rand.Next(1,10)) * -1;                   
        }
        for(int i = 0; i < 10; i++)
        {
            Console.WriteLine(arr[i]);
        }

Sample Output 1 -9 9 -8 1 -4 2 -6 4 -9

Answer 2

Try this:

using System;

namespace ConsoleApp
{
    class Program
    {
        static void Main (string[] args)
        {
            var random = new Random ();

            var array = new int[10];

            for (int i = 0; i < array.Length; i++)
            {
                bool isOdd = (i % 2) == 1; // check remainder

                int randomNumber = random.Next (0, 11); // 0..10

                if (isOdd) randomNumber = -randomNumber; // change sign

                array[i] = randomNumber;
            }
        }
    }
}

Answer 3

This is easier than all the posted answers so far. Here is a basic infinite loop from which to base your specific needs.

    public IEnumerable<int> RandomAlternatingSequence()
    {
        var random = new Random();
        int sign = -1;

        while (true)
        {
            sign *= -1;

            yield return sign * random.Next();
        }
    }

I realize that the post is 2 years old but this may help others who come looking.