Question

I have this method here that gets an object from a JList. The object would then be a string that matches certain values in a hashmap. There are multiple values, for example.

 Course1 - John
 Course2 - John
 Course3 - Mary
 Course4 - Mary

are there any ways to loop through a hashmap and look for certain value, then place both key & value into a string that can then be added to a list model?

Answer 1

If you are searching for values only, use the keySet() method of the hashmap to get the keys and then loop through them to get the corresponding values.

for(String key : hashMap.keySet())
   {
     String value = hashMap.get(key);

     if(searchString.equals(value))
       {
          String keyAndValue = key + value; // this is what you want
       }    
   }

If you are searching for both keys and values, use the entrySet() method of the hashmap to get the entries and then loop through them to look for the match.

 for(Map.Entry<String, String> entry : hashMap.entrySet())
   {
     String key = entry.getKey();
     String value = entry.getValue();

     if(searchString.equals(key) || searchString.equals(value))
       {
          String keyAndValue = key + value; // this is what you want
       }    
   }