How to resolve "'UnityEngine.Random' does not contain a definition for 'Next' ..." error?

Question

i am writing a game in unity and i want to create one random integer number... i am using the following:

public Random ran = new Random();
public int power = ran.Next(0, 10);

but when i want to run the program it gives me the following error:

Type 'UnityEngine.Random' does not contain a definition for 'Next' and no extension method 'Next' of type `UnityEngine.Random' could be found (are you missing a using directive or an assembly reference?)

Does anyone help me on what is going wrong ???

Answer 1

You should use the System.Random class, since this class has a method called Next. For further documentation on this please have a look here. I suppose that this is your error, since from the error message you get, it's clear that the UnityEngine.Random class is used and not the System.Random. In terms of code, I would try this:

public System.Random ran = new System.Random();
public int power = ran.Next(0, 10);

Update

Using the System.Random we will solve the issue of the naming collision but another problem would be arise. Typing the above two lines inside the body of a class, like below:

public class Program
{
    public System.Random ran = new System.Random();
    public int power = ran.Next(0, 10);
}

you will notice that the compiler warns you that something wrong is going on and if you try to build your project, you will get the following message:

A field initializer cannot reference the non-static field, method, or property

In order to fix this, there are two options:

a) Make ran to be static:

public class Program
{
    public static System.Random ran = new System.Random();
    public int power = ran.Next(0, 10);
}

b) Move the initialization of power inside the constructor:

public class Program
{
    public System.Random ran = new System.Random();
    public int power;

    public Program()
    {
       power = ran.Next(0, 10);
    }
}