The first form called the "open if statement" and the second the "closed if statement". The "open" variant is problematic once you have the "else" clause in th

The first form called the "open if statement" and the second the "closed if statement". The "open" variant is problematic once you have the "else" clause in the nested if statements, i.e. it becomes unclear to which "if" each "else" belongs, so the languages had to introduce some complex rules. With the "closed" form everything is straightforward and you don't have this problem. The workaround in C-style languages (C/C++/Java/JS/TS/etc.) is to always put the else clause into the curly brackets, even if it's a single statement. Just to be sure put always both "then" and "else" branches into a curly brackets. It can get even more complicated if you allow "if"-s as ternary operator inside the conditional expressions... Another solution is merging "else if" into an "elif" keyword. So just use "if-then-else-fi" / "if-then-else-end" with an optional "elif".