Random.Range error fix

Unity Courses Show
, ,
1

Hello, if like me you have some error in visual studio in the line where you type only:
Random.Range…
Just add before
UnityEngine
It’ll fix the problem.
UnityEngine.Random.Range
Bye :slight_smile:
François

1 Like
2

Random exists in both UnityEngine and System. If you have something that comes from System (you’ll likely have a using System; at the top) and UnityEngine (you will also have using UnityEngine at the top) you will get this issue.
Your solution to use the fully-qualified name is valid, but you could also use an alias

using System;
using UnityEngine;
using Random = UnityEngine.Random;

Here we gave an alias called Random that will always be the one from UnityEngine

3

Hello Bixarrio.
Why in the course there isn’t the problem ?
For me if I don’t put UnityEngine before Random, I this message :
‘Random’ is an ambiguous reference between ‘UnityEngine.Random’ and ‘System.Random’
In the course in the other functions like ShouldRandomDrop, GetRandomNumberOfDrops and SelectRandomItem there no need to add something else.
I use Unity 2022.3.14f1
Thank you.
François

4

Because Sam opted to not have the using System; and instead fully qualify the parts that is from System. The methods you mention are from the DropLibrary. In there, you have a DropConfig that needs to be Serializable. Serializable is an attribute in System and Sam chose to use it like

[System.Serializable] // <- Fully-qualified
class DropConfig

When you put the using bits at the top, the whole file knows about everything that is in the namespace you mention. If you have using UnityEngine; the whole file knows about everything that’s in UnityEngine; Random, Vector2, Vector3, MonoBehaviour, etc. If you add using System;, the file now also knows about everything that’s in System - and this also has a type called Random. Now the compiler doesn’t know which Random you want to use. You can tell it by:

  • fully qualifying where this random is (like your original post) int randomIndex = UnityEngine.Random.Range(0, list.Length);, or
  • by using an alias (like I mentioned in my original post) using Random = UnityEngine.Random;. An alias is just that; an alias. It doesn’t have to be called Random, you can call it whatever you want. using Fred = UnityEngine.Random; will work, too. Random makes more sense, though. Or
  • by fully qualifying the stuff from System (like Sam did) and then it won’t clash either
5

Clear, high and strong.
Thanks to have spent time to explain this ambiguous interpretation.
Have a nice day.
Take care.
François