R语言if else语句的问题

Question

> a<-function(x){if(x<0) x-1;elseif(x>=0&x<5) x+1;x+2}
Error: unexpected symbol in "a<-function(x){if(x<0) x-1;elseif(x>=0&x<5) x"
> for(i in 1:20){if (i<5) s[i]<-5;elseif (i>=5&i<=10) s[i]<-6;else s[i]<-7}
Error: unexpected symbol in "for(i in 1:20){if (i<5) s[i]<-5;elseif (i>=5&i<=10) s"
请问上述公式问题如何调整

Answer 1

a <- function(x){
if(x < 0){
result = x-1
}else if(x >=0 & x < 5){
result = x-1
}else{
result = x+2
}
return(result)
}