How do I generate random number between 0 and 1 in C#?

Question

I want to get the random number between 1 and 0. However, I'm getting 0 every single time. Can someone explain me the reason why I and getting 0 all the time? This is the code I have tried.

Random random = new Random(); int test = random.Next(0, 1); Console.WriteLine(test); Console.ReadKey(); 

Answer 1

According to the documentation, Next returns an integer random number between the (inclusive) minimum and the (exclusive) maximum:

Return Value

A 32-bit signed integer greater than or equal to minValue and less than maxValue; that is, the range of return values includes minValue but not maxValue. If minValue equals maxValue, minValue is returned.

The only integer number which fulfills

0 <= x < 1 

is 0, hence you always get the value 0. In other words, 0 is the only integer that is within the half-closed interval [0, 1).

So, if you are actually interested in the integer values 0 or 1, then use 2 as upper bound:

var n = random.Next(0, 2); 

If instead you want to get a decimal between 0 and 1, try:

var n = random.NextDouble(); 

Hope this helps :-)

Answer 2

You could, but you should do it this way:

double test = random.NextDouble(); 

If you wanted to get random integer ( 0 or 1), you should set upper bound to 2, because it is exclusive

int test = random.Next(0, 2);