&& and || are not if

a && b runs b only if a succeeded. a || b runs b only if a failed. So far so good.

But they have the same precedence and group to the left, so a || b && c runs as (a || b) && c — which is not what the English words suggest, and is a real source of scripts that do the wrong thing on the failure path.

The a && b || c idiom is the one to be careful with. It reads like if-then-else and is not: if b itself fails, c runs too.

When you mean if-then-else, write if. It is three more words and it cannot surprise you.