Selecting random key and value sets from a Map in Java

java dictionary random hashmap treemap
Roberto picture Roberto · Mar 29, 2012 · Viewed 42.4k times · Source

I want to get random keys and their respective values from a Map. The idea is that a random generator would pick a key and display that value. The tricky part is that both key and value will be strings, for example myMap.put("Geddy", "Lee").

Answer

synopia picture synopia · Mar 29, 2012 
HashMap<String, String> x;

Random       random    = new Random();
List<String> keys      = new ArrayList<String>(x.keySet());
String       randomKey = keys.get( random.nextInt(keys.size()) );
String       value     = x.get(randomKey);

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