Question

I am creating Dictionary and an ArrayList such as this.

Dictionary testDict, testDict2 = null;
ArrayList al = new ArrayList();

testDict.put ("key1", dataVar1);
testDict.put ("key2", dataVar2);
testDict2.put ("key1", dataVar1);
testDict2.put ("key2", dataVar2);

al.add(testDict);
al.add(testDict2);

now my issue here is, how can I access the data within the dictionaries? Like for example how would I retrieve key1 from testDict using al?

Many thanks in advance 🙂

Answer 1

As you can read in the Java Docs all Dictionary objects (note that e.g. Hashtable is one of them) have a method Object get(Object key) to access it’s elements. In your example you could access the value of the entry key1 in textDict like that:

// first access testDict at index 0 in the ArrayList al 
// and then it's element with key "key1"
al.get(0).get("key1");

Note, that you nowhere initialize your Dictionary objects and that the Dictionary class is abstract. So you could for example use a Hashtable (or if you don’t need synchronized access use a faster HashMap instead) for your purpose like this:

testDict = new Hashtable<String, String>();

And make sure to use the correct generic types (the second one has to be the type that your dataVars have)