[R] print(cat(bleh)) shows up strange NULL

Dan Bolser dmb at mrc-dunn.cam.ac.uk
Tue Jan 4 23:44:30 CET 2005


On 4 Jan 2005, Peter Dalgaard wrote:

>Dan Bolser <dmb at mrc-dunn.cam.ac.uk> writes:
>
>> I am trying the following code...
>> 
>> for(i in 1:bins){
>>   print(cat(c(i, length(var1[var1==i]))))
>> }
>> 
>> Where var1 is a vector with zero or more values = {1, 2, ..., bins} (or
>> something like that).
>> 
>> The result I get is...
>> 
>> 1 33NULL
>> 2 28NULL
>............
>> 19 0NULL
>> 20 3NULL
>> 
>> I don't know what I am doing to get those stray NULL characters printed.
>
>You're printing them, will you believe it...?
> 
>Consider this:
>
>> x <- cat("abc")
>abc> print(x)
>NULL
>> x
>NULL
>> print(cat("abc"))
>abcNULL
>
>I.e. cat() always returns NULL, invisibly unless you force it to be
>printed. 

never trust a cat!

>
>
>




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