Finding Combinations of two characters by id in a dataset in R

Question

I have a dataset sorted by IDs and several fruits. What I want to do is detect all possible combinations of 2 fruits dependent on the ID without repetition (Apple-Banana combination should be the same as Banana-Apple).

As an example:

ID	Fruit
1	Apple
1	Banana
1	Blueberry
2	Apple
3	Orange
3	Banana
3	Apple
3	Blueberry

What I want to create is:

ID	Combination
1	Apple Banana
1	Apple Blueberry
1	Banana Blueberry
2	Apple
3	Banana Orange
3	Apple Orange
3	Blueberry Orange
3	Apple Banana
3	Banana Blueberry
3	Apple Blueberry

The example dataset:

ID <- c(1,1,1,2,3,3,3,3)
Fruit <- c("Apple","Banana","Blueberry","Apple","Orange","Banana","Apple","Blueberry")
dataset <- data.frame(ID, Fruit)

Answer 1

This is for reference.

uniID=unique(dataset$ID)
res=NULL
for (id in 1:length(uniID))
{
    sameIDdf=dataset[dataset$ID==id, ]
    x=nrow(sameIDdf)
    print(x)
    if (x>1)
    {
       comb=t(combn(1:x, 2))
       for (i in 1:nrow(comb))
       {
         res=rbind(res, data.frame(ID=id, Combination=paste(sameIDdf[comb[i,1], 'Fruit'], sameIDdf[comb[i,2], 'Fruit'])))
       }
    } else
    {
        res=rbind(res, data.frame(ID=id,Combination=sameIDdf[1,'Fruit']))
    }    
}
res

Result:

ID  Combination
<int>   <fct>
1   Apple Banana
1   Apple Blueberry
1   Banana Blueberry
2   Apple
3   Orange Banana
3   Orange Apple
3   Orange Blueberry
3   Banana Apple
3   Banana Blueberry
3   Apple Blueberry