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Thread: How to print out all keys cerrently stored in a HashMap?

  1. #1
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    Default How to print out all keys cerrently stored in a HashMap?

    I want to write a method to print the all the names of a phone book. phoneBook is a HashMap<String, String> , that has names as keys and phone numbers as values.

    Reading the documentation for both HashMap and Set, I have more or less an idea of how it could be done but I cant put it on code..
     
    public String getName()
        {
     
            String[] keys = phoneBook.keySet().toArray();
            return keys[0];
     
        }

    This is wrong. It doesnt compile saying incompatible types. I was thinking first to manage to succeed to get a key from my phone book and then I change it to print all the keys.
    Is this possible with this way of thinking?


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    Default Re: How to print out all keys cerrently stored in a HashMap?

    Use the API. What does Set.toArray() return?

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    Default Re: How to print out all keys cerrently stored in a HashMap?

    Nice one...I understood your point. I need the other toArray method that specify the return type Cheers!!!!!

    p.s. The Set.toArray() returns an Array of Set? (I ask to confirm that I completely understood)

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    Default Re: How to print out all keys cerrently stored in a HashMap?

    Did you consult the Set API?

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