The Condition Has Length 1 And Only The First Element Will Be Used

How to resolve the error the condition has length > 1 and only the first element will be used?

 I created a program something like this

a<-function(x) {

if (x<0){

a<-0

return(a)

}else{

a<-2+a

return(a)

}

    }

Which is displaying an error called In if (t < 0) {: the condition has length > 1 and only the first element will be used