Get values from an array stored inside a map

Question

I have a map with integer keys and corresponding values of arrays of strings. I want to get a get a value out of that array from inside the map and am having a heck of a time doing this. My searches haven't yielded anything useful other than the recommendation to 'wrap it' and I'm really not sure what that means! Here is an example:

Map myTasks = new HashMap();

myTasks.put(1, new String[] {"cake"});
myTasks.put(15, new String[] {"bake"});

String myString = myTasks.get(1)[0];  // This doesn't work.

So I have picked up that myTasks.get(1) returns an object. How do I get a string value out of that object?

Thank you!

pL4Gu33 · Accepted Answer · 2014-07-12 08:00:02Z

2

You can also use Generics for it:

public static void main(String[] args) {
    Map<Integer, String[]> myTasks = new HashMap<Integer, String[]>();

    myTasks.put(1, new String[] {"cake"});
    myTasks.put(15, new String[] {"bake"});

    String myString = myTasks.get(1)[0];
    System.out.println(myString);
}

answered Jul 12, 2014 at 8:00

pL4Gu33

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Vinay Bhargav · Accepted Answer · 2014-07-12 08:03:07Z

2

Problem in your code is, you are trying to access an object as array directly.

Try this-

Map myTasks = new HashMap();

myTasks.put(1, new String[] {"cake"});
myTasks.put(15, new String[] {"bake"});

String[] myString = (String[]) myTasks.get(1);
System.out.println(myString[0]);

All you have to do is typecast the object.

Best practice is to use-

Map<Integer, String[]> myTasks = new HashMap<Integer, String[]>();

Instead of Map myTasks = new HashMap(); with which you don't need to typecast.

edited Jul 12, 2014 at 8:03

answered Jul 12, 2014 at 7:56

Vinay Bhargav

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Comments

mayr · Accepted Answer · 2014-07-12 07:59:40Z

1

Add generic type:

Map<Integer, String[]> myTasks = new HashMap<Integer, String[]>();

answered Jul 12, 2014 at 7:59

mayr

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