Thread: Method Help?

How can I create a method that uses a HashSet and will return the unique characters in a string?
for example
unique("racecar") ----> "e"
unique("confuse") ----> "confuse"


Thank you.

Thank you for the input, however, I am still unsure as to what the actual code for this would look like. Can anyone provide some code for me?

Look at the HashSet add method for one tool to use.

 
import java.util.TreeMap;
 
 
public class IFailAtJava {
	public static void main(String[] args){
 
	}
	public void unique(String[] s){
		String[] word = s;
		TreeMap<String, Integer> map = new TreeMap<String, Integer>();
		for(int i = 0; i < word.length; i++){
			String key = word[i];
			if(map.get(key) == null){
				map.put(key, 1);
			}
			else{
				int value = map.get(key).intValue();
				value++;
				map.put(key, value);
 
 
			}
 
 
 
 
 
 
 
 
			}
		System.out.println(map);
 
 
		}
 
 
 
	}

This is what I have so far, however I cannot figure out how to actually get the code to return the unique characters.

 
import java.util.TreeMap;
 
public class IFailAtJava {
	public static void main(String[] args) {
 
	}
 
	public String[] unique(String[] s) {
		String[] word = s;
		TreeMap<String, Integer> map = new TreeMap<String, Integer>();
		for (int i = 0; i < word.length; i++) {
			String key = word[i];
			if (map.get(key) == null) {
				map.put(key, 1);
			} else {
				int value = map.get(key).intValue();
				value++;
				map.put(key, value);
 
			}
			for (int j = 0; j < word.length; j++) {
				if (map.get(key) > 1) {
					map.remove(key);
 
				}
 
			}
 
		}
		return word;
 
	}
 
}

This is what I have added to the method, however I cannot get it to return anything without causing return type problems.

Look at using a second HashSet to save the dup entries discovered when adding to a first HashSet. After all strings added to the first, use the removeAll method to generate a unique list.