C# | Random.NextDouble() Method

The NextDouble() Method of System.Random class in C# is used to return a random floating-point number which is greater than or equal to 0.0, and less than 1.0.

Syntax:

public virtual double NextDouble();

Return Value: This method returns a double-precision floating point number which is greater than or equal to 0.0, and less than 1.0.

Below program illustrates the use of NextDouble() Method:

Example 1:

// C# program to illustrate the
// Random.NextDouble() Method
using System;

class GFG {

    // Driver code
    public static void Main()
    {
        // Instantiate random number generator
        Random rand = new Random();

        // Print 10 random floating point numbers
        Console.WriteLine("Printing 10 random floating point numbers");
        for (int i = 0; i < 10; i++)
            Console.WriteLine("{0} -> {1}", i, rand.NextDouble());
    }
}

Output:

Printing 10 random floating point numbers
0 -> 0.0227202852362396
1 -> 0.624568469647583
2 -> 0.0145442797870116
3 -> 0.646489209330869
4 -> 0.967497945748036
5 -> 0.839329582098559
6 -> 0.873648912121378
7 -> 0.16200648022909
8 -> 0.66018275761054
9 -> 0.0837694853934317

Example 2:

// C# program to illustrate the
// Random.NextDouble() Method
using System;

class GFG {

    // Driver code
    public static void Main()
    {
        // Instantiate random number generator
        Random rand = new Random();

        // Instantiate an array of double
        double[] a = new double[10];

        // Store random floating point
        // numbers in the array
        for (int i = 0; i < 10; i++)
            a[i] = rand.NextDouble();

        // Print 10 random floating point numbers
        Console.WriteLine("Printing 10 random "+
                      "floating point numbers");

        for (int i = 0; i < 10; i++)
            Console.WriteLine("{0} -> {1}", i, a[i]);
    }
}

Output:

Printing 10 random floating point numbers
0 -> 0.853536825558886
1 -> 0.741455778359182
2 -> 0.496043408986201
3 -> 0.0975164361752181
4 -> 0.120282317567748
5 -> 0.57163705703413
6 -> 0.749181974562435
7 -> 0.684014179596684
8 -> 0.691246760865323
9 -> 0.888019556127498

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.random.nextdouble?view=netframework-4.7.2