How to take away 1 from buildindex?

Good day everyone,

My game's 'scenes in build' are configured like this:


I have text in every scene as part of a canvas that tells the player what level they are on.
When I'm on level1 (scene 2), I want this text to say level: followed by 1.
Right now, I have this

Code (CSharp):

1. levelText.text = "Level: " + SceneManager.GetActiveScene().buildIndex;

Now of course, when I'm on level 1, this will just display 2 as the buildindex is 2.
I can do

Code (CSharp):

1. levelText.text = "Level: " + SceneManager.GetActiveScene().buildIndex + 1;

That works fine and it comes out with 3.
When I replace the +1 with -1, it gives me this error


That is literally it.

I do not understand why this doesn't work. It may be a stupid question but I beg someone helps me.

I understand the error it's telling me, I think the BuildIndex is coming out as a string and the -1 is taking away an integer which shouldn't work but how come it works when I do +1?

Thanks,

 

Put parentheses around (SceneManager.GetActiveScene().buildIndex - 1). That'll treat that as int math, before combining with the string.

(I'm actually quite surprised that your example with + DOES work - I would fully expect it to show "Level: 21" if you're on scene 2.)

 

I'm also surprised to see that behaviour (although I would not have expected a "Level 21" (if you are on scene 2 as StarManta suggested)), I would have expected the same error from the compiler because it is ambiguous. I can only surmise that this is because of some special treatment that '+' receives: "+" is overloaded for strings, '-' isn't (which is probably why StarManta expected the result to be '21'). Checking the operator precedence table also doesn't clear this up, so I'm guessing that this is simply an imbalance that Unity left in there: the code is smart enough to check if a '+' is followed by the same type to wait with the implicit ToString(), but fails to do so for '-'.

Strange indeed.

[Edited for incorrectly quoting Star Manta. My apologies]

 

He says buildIndex is 2, not 1.

 

Thank you so much for helping out
It was pretty simple but I just didn't know. Love the community on Unity so far, helped me out so much as a beginner lmao