why +=1 works, but ++ doesn' ?

GameObject.Find(“Main Camera”).GetComponent(“PreScore”).fours+=1;
but

GameObject.Find("Main Camera").GetComponent("PreScore").fours++;

returns error BCE0049: Expression ‘GameObject.Find(“Main Camera”).GetComponent(“PreScore”).fours’ cannot be assigned to. Why?

I believe Berenger is right

I think the reason is because in the really long task you basically end up with a reference of a variable with which the += can then change.

but because its more of a reference than an actual variable you cant use the ++

now I bet that if you set that look up task to a variable then tried using ++ it would work

Im HORRIBLE with the technical jargon
but +=is like a real operation
where as ++ is more exclusive