C# Random NextDouble

Description

Random NextDouble returns a random floating-point number between 0.0 and 1.0.

Syntax

Random.NextDouble has the following syntax.


public virtual double NextDouble()

Returns

Random.NextDouble method returns A double-precision floating point number greater than or equal to 0.0, and less than 1.0.

Example

The following example uses the NextDouble method to generate sequences of random doubles.


using System;/*  ww  w. jav  a2  s. c  o  m*/
using System.Threading;

public class RandomObjectDemo  
{
    static void Main( )
    {  
        Random randObj = new Random();
        // Generate the first six random doubles. 
        for( int j = 0; j < 6; j++ )
            Console.Write( " {0:F8} ", randObj.NextDouble( ) );

    }
}

The code above generates the following result.

Example 2

The following example calls the NextDouble method to generate 100 random numbers and displays their frequency distribution.


using System;/*  w  w w  .  j  a v  a2 s  .c  o m*/

public class Example
{
   public static void Main()
   {
      int[] frequency = new int[10];
      double number;
      Random rnd = new Random();

      for (int ctr = 0; ctr <= 99; ctr++) {
         number = rnd.NextDouble();
         frequency[(int) Math.Floor(number*10)] ++;
      }
      Console.WriteLine("Distribution of Random Numbers:");
      for (int ctr = frequency.GetLowerBound(0); ctr <= frequency.GetUpperBound(0); ctr++)
         Console.WriteLine("0.{0}0-0.{0}9       {1}", ctr, frequency[ctr]);
   }
}

The code above generates the following result.