Java queue and multi-dimension array

Question

First of all, this is my code (just started learning java):

Queue<String> qe = new LinkedList<String>();

qe.add("b");
qe.add("a");
qe.add("c");
qe.add("d");
qe.add("e");

My question:

1. Is it possible to add element to the queue with two values, like:

   qe.add("a","1"); // where 1 is integer

So, that I know element "a" have value 1. If I want to add a number let say "2" to element a, I will have like a => 3.

If this cant be done, what else in java classes that can handle this? I tried to use multi-dimention array, but its kinda hard to do the queue, like pop, push etc. (Maybe I am wrong)

1. How to call specific element in the queue? Like, call element a, to check its value.

[Note]

Please don't give me links that ask me to read java docs. I was reading, and I still dont get it. The reason why I ask here is because, I know I can find the answer faster and easier.

Answer 1

You want to use a HashMap instead of LinkedList. HashMap is a dictionary-like structure that allows you to create associations, for instance a=>1.

Check out JavaDocs for HashMap to get a grasp how to use it:-).

Answer 2

I think you're asking for a dictionary type in Java.

Map<String, Integer> map = new HashMap<String, Integer>();
map.put("a", 1);
map.put("b", 2);

You can then access them by key - in this case the String you choose as the key.

int value = map.get("a");

Value in this case will return 1.

Is that what you want?

Answer 3

You'd want to combine a Queue<K> with a Map<K,V>:

• Put the keys (e.g. "a", "b") into the Queue<K>
• Assign the mapping of the keys to values (e.g. "a"=>3) in the Map<K,V>