I currently have some array lists and am trying to transfer some elements into a different array.   Here's what I have so far:  //create array separate from user input to remove duplicates  ArrayList&lt;String&gt; idsWithoutDuplicates  = new ArrayList&lt;String&gt;(); for (int i = 0; i &lt; missionIds.size(); i++){     if (idsWithoutDuplicates.contains(missionIds.get(i))== false)         idsWithoutDuplicates.add(missionIds.get(i));  }  //search for mission numbers within array of array  for (int k = 0; k &lt; idsWithoutDuplicates.size(); k++ ){     int idSize=0;     for (int employeeName = 0; employeeName &lt;ids.size(); employeeName++){         for (int employeeId = 0; employeeId &lt;ids.get(employeeName).size(); employeeId++){             /* when id is located, use the employee array to locate the other missions to               * which they belong */             if (ids.get(employeeName).get(employeeId).equals(idsWithoutDuplicates.get(k))){                 for (employeeId = 0; employeeId &lt; ids.get(employeeName).size(); employeeId++){                     ArrayList&lt;String&gt; count  = new ArrayList&lt;String&gt;(); // ---&gt; separate array for each employees total missions                     if (ids.get(employeeName).get(employeeId).equals(idsWithoutDuplicates.get(k)) == false &amp;&amp;                          count.contains(ids.get(employeeName).get(employeeId))== false){                         count.add(ids.get(employeeName).get(employeeId));                           idSize += count.size();                           for (int i= 0; i &lt; count.size(); i++){                             System.out.print(count.get(i));                         }                     }                 }             }         }     }     System.out.println(idsWithoutDuplicates.get(k) + "\t    " + idSize);  }   The last if statement is trying to eliminate any duplicates with the contains condition, but this doesn't seem to work. I've tried converting 'count' to a set but this didn't work either.
I have an ArrayList&lt;String&gt;, and I want to remove repeated strings from it. How can I do this?
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