Question

The compiler complains about this code:

    HashMap<String,int> userName2ind = new HashMap<String,int>();
    for (int i=0; i<=players.length; i++) {
        userName2ind.put(orderedUserNames[i],i+1);
    }

It writes “unexpected type” and point on int. If I replace int by String and i+1 by i+"1", the compilation goes OK. What is wrong with in here?

Answer 1

It’s fine with Integer, but not okay with int – Java generics only work with reference types, basically 🙁

Try this – although be aware it will box everything:

HashMap<String,Integer> userName2ind = new HashMap<String,Integer>();
for (int i=0; i<=players.length; i++) {
    userName2ind.put(orderedUserNames[i],i+1);
}