Apps Help with putStringSet and getStringSet method

[Anza87]

I understand now methods putString and getString for saving one string for example,
but I want to save some array of strings, for example 5 strings. I
found this two methods(putStringSet, getStringSet), but I don't know
how to fill Set<String> with strings. Can anybody help me? tnx
public abstract SharedPreferences.Editor putStringSet (String key, Set<String> values)

public abstract Set<String> getStringSet (String key, Set<String> defValues)




http://developer.android.com/refere...lang.String, java.util.Set<java.lang.String>)

 

[Kostas G]

You can use the following code:

Set<String> defValues = new HashSet<String>();

defValues.add("string 1");
defValues.add("string 2");
defValues.add("string 3");

 

[Anza87]

Thanks. I save now in my project some strings in HashSet, like you show me. What is now the easiest way to read this strings out from HashSet like defValues, for example?

 

[Kostas G]

This is as simple as that:

for(String s: defValues) {
    doSomethingWithString(s);
}

 

[Anza87]

What will code look like, if I want to read just 2nd string for example?

 

[Kostas G]

The Set interface doesn't provide a method for random accessing of elements. Worse than that, the interface doesn't guarantee anything about the order of the elements. So, you can use the following code:

int i = 0;
for(String s: defValues) {
    if (i == 1) {
        // do something with the second element
     
        break;
    } 
    i++; 
}

but that doesn't mean that you will get the string that you've inserted second. You could use the LinkedHashSet implementation, which provides a predictable iteration order, but you would still need to access a random element with the above cumbersome way.

If random access is important for you, I suggest that you hold your Strings in a List container. Create a Set out of the List, when you need to use it. Be warned that duplicate elements are allowed in a List, but not in a Set.