C# | Random.NextDouble() Method

Last Updated : 01 May, 2019

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: