Question

I am having some difficulty in using the function else in R.
When I input ?else, I didn’t get any help about the function else.

When I run the following program:

i=1

if(i>1){print("aa")}

else{print("bb")}

the else didn’t work. Can someone tell me the reasons?

Answer 1

to get help type

?'else'

look at the paragraph in help

Note that it is a common mistake to forget to put braces ({ .. }) around your statements, e.g., after if(..) or for(….). In particular, you should not have a newline between } and else to avoid a syntax error in entering a if … else construct at the keyboard or via source. For that reason, one (somewhat extreme) attitude of defensive programming is to always use braces, e.g., for if clauses.

if(i>1){print("aa")
}else{print("bb")}

or

if(i>1){print("aa")}else{print("bb")}

will presumably work for you.

i=1

{
if(i>1){print("aa")}
else{print("bb")}
}

would also work. The key is to let the parser know to expect more input.