java - Why HashSet or HashMap does not support position based accessed? However these class also store object in array of type enter -

i have checked in source code of hashmap @ grepcode.com , found store object hashcode in array.

transient entry[] table;    public v put(k key, v value) {          if (key == null)              return putfornullkey(value);          int hash = hash(key.hashcode());          int = indexfor(hash, table.length);          (entry<k,v> e = table[i]; e != null; e = e.next) {              object k;              if (e.hash == hash && ((k = e.key) == key || key.equals(k))) {                  v oldvalue = e.value;                  e.value = value;                  e.recordaccess(this);                  return oldvalue;              }          }           modcount++;          addentry(hash, key, value, i);          return null;      }   void addentry(int hash, k key, v value, int bucketindex) {          entry<k,v> e = table[bucketindex];          table[bucketindex] = new entry<k,v>(hash, key, value, e);          if (size++ >= threshold)              resize(2 * table.length); } 

please suggest.

yes true internally hashmap/hashset uses arrays. neither saving or retrieval these arrays sequential. reason simple: these collections use hashing decide bucket store , retrieve objects. hash calcualted each entry not sequential number. , hash of each element used store , retrieve entries these collections.