Re: HashMap problem: insert with hash code retrieve by index
On Apr 27, 4:50 pm, Royan <romayan...@gmail.com> wrote:
Lets say we have the following class
public class Foo {
private Map<Integer, String> dataMap = new HashMap<Integer,
String>();
public String getValueAt(int idx) {
// I wish I don't use for loop here ...
}
public void addValue(String s) {
String l = dataMap.put(getHashCode(s), s);
}
}
The problem is that I have to fill the map with values that are
absolutely inconsistent with each other, they are actually hash codes,
but when I call getValueAt method I need to get an element that would
be taken from Nth position.
Assume I have the following code
Foo f = new Foo();
f.addValue("qwerty");
f.addValue("12345");
// i know that the size of the HashMap is 2, so the following must be
fair
f.getValueAt(0); // OK
f.getValueAt(1); // OK
f.getValueAt(2); // ERROR - out of range
I do understand that the order of extraction in HashMap is unpredicted
- this is OK, but what is the best way to implement the functionality
that would help me extract elements from that map by an absolute index?
Do you have a good reason not to use ArrayList for this? You'd get
the same complexity without introducing a class that does nothing more
than make a hashmap look like a subset of the List interface.
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