Collections Queries in Java.

[Deepak Lal]

I have below questions in Collections with respect to Java.

1> Suppose i have SSN(Social Security Number) as Key in Hashmap,The Value in HashMap being a combination of (customer name,customer address,customer pincode)

HashMap [key,Value]-->[SSN,(customer name,customer address,customer pincode)]

what datastructure i would use for the above implementation in Java and how would i retrieve customer details(name,address,pincode) based on SSN.Example for the above implementation provided will be helpful.


2> I have HashMap of [Key,Value] pair -> [bank account number,telephone no]

HashMap has got 3 entries
Ex:HashMap m = new HashMap();
m.put("12345","08026583026");
m.put("12346","08026583027");
m.put("12347","08026583028");

How do i retrieve telephone number based on bank account number,assume user inputs 12347 and the the result should be 08026583028 ??Example for the above implementation provided will be helpful.??



3> I have HashMap of [Key,Value] -> [telephone no,bank account number]

HashMap has got 3 entries
Ex:HashMap m = new HashMap();
m.put("08026583026","12345");
m.put("08026583027","12346");
m.put("08026583028","12347");
How do i retrieve bank account number based on telephone number,assume user inputs 08026583028 and the the result should be 12347 ??Example for the above implementation provided will be helpful.??

4> Give the Implementation /Algorithm to control 3 elevators in Core Java ??

Help provided will ne highly appreciated.

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Deepak Lal

[Angel Taveras]

Hello Deepak, the approach below can be used for 1,2,3.

You could create a class Customer that has a (name,address,pincode) properties in it, even the SSN. Then put the SSN as key in the map. Like this
Map.put(SSN,customerInstance).

regards,

[Garrett Rowe]

For 1: Do you know how to create a simple class in Java with instance fields and accessor methods?

For 2-3: I would look to the API of java.util.HashMap. You should be able to find a method that takes a key as a parameter and returns the corresponding object that was stored in the Map.

For 4: You'll have to work that out on your own. We don't do other peoples homework around here.

[Deepak Lal]

Hi Angel and Garett,
Can you give me a example on how to proceed for Question 1,2,3.
I'm finding it a bit difficult to implement.If you can provide me with the implementation for the same.it would be helpful.

Help provided will be highly appreciated.

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Deepak Lal

[Rob Spoor]

Please Show Some Effort. Problems 2 and 3 are basically the same (how to get the value for a key) and Garrett has given you a hint to find the single method you need for this.

And I can't believe you don't know how to create the Customer class Angel has described. You've been on this board long enough to at least be able to create such a simple thing.