if - else if - else statement and brackets

Question

According to what I've learned, the standard approach to write a "if - else if" sentence is as follows:

If (2==1), print("1"), else if (2==2), print("2"), otherwise print("3")
or

if (2==1) print("1") else print("2") if (2==2) print("2") else print ("3")
Quite the opposite, If I continue to write in this manner,

if (2==1) print("1") otherwise (print("3") or this way: if (2==2) print("2") else (print("3")

The statement does not work if (2==1) print("1") otherwise if (2==2) print("2") else print("3") Can you explain why else or else must come before else or else if they're on the same line? Is there any way to write the if-else if-else sentence in R without using brackets?

Answer 1

When the first if is followed by a compound expression (marked by the pair), the parser will assume that the expression after else is compound as well. The only time else is explicitly used is in compound expressions. This is mentioned explicitly in the documentation: if(cond) cons.expr else alt.expr, where cons.expr and alt.expr are both compound. You can work around this by using the way R parses function definitions, as @Berry mentioned, but it's better to be consistent with bracket usage (IMO). – hrbrmstr hrbrmstr hrbrmstr
 

It will also work if you surround the uncommon if-else in brackets (bad if-else expr) or in a function (function()) that is more common (bad if-else expr) –

rawr