Ifelse() with three conditions

Question

I have two vectors:

a<-rep(1:2,100)

b<-sample(a)

I would like to have an ifelse condition that compares each value of a

Answer 1

There is ambiguity in your question. Do you want different random values for all indexes where a==b or one random value for all indexes?

The answer by @Rob will work in the second scenario. For the first scenario I suggest avoiding ifelse:

u<-rep(NA,length(a))
u[a>b] <- 1
u[a