What happens if the Supreme Court rules like this?

[I spent the winter writing songs about getting better]

Someone brings a case against some law. SCOTUS takes the case.

Four justices rule in favor of the plaintiff and hold the law should be struck down. Four justices rule to uphold the law. The ninth justice sidesteps the law's constitutionality question entirely and just rules that the case is invalid on a technicality, such as that the plaintiff didn't have standing to sue or whatever.

Obviously the law is upheld, but what's the decision? It seems weird the ninth justice gets to write it when none of the others agree. Do both of the main sides get to write a dissent?