how to create random number in c# code example

Example 1: c# random int

Random rnd = new Random();
int number  = rnd.Next(1, 10);

Example 2: c# generate random number

// Creates a random number between 1 and 10
int randomNumber = new Random().Next(1, 11);

Example 3: c# random

const long ONE_TENTH = 922337203685477581;

Random rnd = new Random();
double number;
int[] count = new int[10];

// Generate 20 million integer values between.
for (int ctr = 1; ctr <= 20000000; ctr++) {
   number = rnd.NextDouble() * Int64.MaxValue;
   // Categorize random numbers into 10 groups.
   count[(int) (number / ONE_TENTH)]++;
}
// Display breakdown by range.
Console.WriteLine("{0,28} {1,32}   {2,7}\n", "Range", "Count", "Pct.");
for (int ctr = 0; ctr <= 9; ctr++)
   Console.WriteLine("{0,25:N0}-{1,25:N0}  {2,8:N0}   {3,7:P2}", ctr * ONE_TENTH,
                      ctr < 9 ? ctr * ONE_TENTH + ONE_TENTH - 1 : Int64.MaxValue,
                      count[ctr], count[ctr]/20000000.0);

// The example displays output like the following:
//                           Range                            Count      Pct.
//
//                            0-  922,337,203,685,477,580  1,996,148    9.98 %
//      922,337,203,685,477,581-1,844,674,407,370,955,161  2,000,293   10.00 %
//    1,844,674,407,370,955,162-2,767,011,611,056,432,742  2,000,094   10.00 %
//    2,767,011,611,056,432,743-3,689,348,814,741,910,323  2,000,159   10.00 %
//    3,689,348,814,741,910,324-4,611,686,018,427,387,904  1,999,552   10.00 %
//    4,611,686,018,427,387,905-5,534,023,222,112,865,485  1,998,248    9.99 %
//    5,534,023,222,112,865,486-6,456,360,425,798,343,066  2,000,696   10.00 %
//    6,456,360,425,798,343,067-7,378,697,629,483,820,647  2,001,637   10.01 %
//    7,378,697,629,483,820,648-8,301,034,833,169,298,228  2,002,870   10.01 %
//    8,301,034,833,169,298,229-9,223,372,036,854,775,807  2,000,303   10.00 %

Example 4: c# random

Random rnd = new Random();
string[] malePetNames = { "Rufus", "Bear", "Dakota", "Fido",
                          "Vanya", "Samuel", "Koani", "Volodya",
                          "Prince", "Yiska" };
string[] femalePetNames = { "Maggie", "Penny", "Saya", "Princess",
                            "Abby", "Laila", "Sadie", "Olivia",
                            "Starlight", "Talla" };

// Generate random indexes for pet names.
int mIndex = rnd.Next(malePetNames.Length);
int fIndex = rnd.Next(femalePetNames.Length);

// Display the result.
Console.WriteLine("Suggested pet name of the day: ");
Console.WriteLine("   For a male:     {0}", malePetNames[mIndex]);
Console.WriteLine("   For a female:   {0}", femalePetNames[fIndex]);

// The example displays output similar to the following:
//       Suggested pet name of the day:
//          For a male:     Koani
//          For a female:   Maggie