[R] simple if...else causes syntax error

[Uwe Ligges]

roger bos wrote:

> I am trying to do the simplest thing in the world.  The following works:
> 
> aaa <- ifelse(aaa==5, 6, 7)            
>             
> But if I want to change the if...else syntax instead, it gives errors
> and assigns 7 to aaa.  Here is the problem code:
> 
> aaa <- 5
> if ( aaa==5 ) { 
>    aaa <- 6
> }
> else {
>    aaa <- 7
> }
>             
> Here is the output:
> 
> 
>>aaa <- 5
>>            if ( aaa==5 ) { 
> 
> +             aaa <- 6
> +   }
> 
>>            else {
> 
> Error: syntax error
> 
>>aaa <- 7
>>}
> 
> Error: syntax error
> 
>>            
> 
> 
> Hope someone can solve this easy question for me.
> 
> BTW, how come "?if" does not pull up the help file for the 'if' statement?

Parser, try ?"if"


And in ?"if" read the Details section, which tells you:

"[...] In particular, you should not have a newline between } and else 
to avoid a syntax error [...]".


The point is that
    if(A)
        B
is already syntactically complete (else can be omitted), so what the 
parser does not know what follows and has to evaluate ...


Uwe Ligges





> Thanks,
> 
> Roger
> 
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