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String set to ArrayList? [closed]

So I was looking up how to change a String set to an ArrayList<sSring> and I couldn't find anything. I tried:

favorites  = new ArrayList( mPrefsaved.getStringSet("faves", null) ;

How can I convert a StringSet into an ArrayList<string>?

I tried:

  private void getsaved() {

      favorites = new ArrayList<String>(mPrefsaved.getStringSet("faves", null));

}

But log Cat told me NullPointerException

like image 229
JavaGrassHopper Avatar asked Dec 26 '13 15:12

JavaGrassHopper


2 Answers

Consider you have a set of Strings like

Set<String>  set = new HashSet<String>();
 // some elements in set

then you can try

 List<String>  listFromSet = new ArrayList<String>(yourCurrentSet);

in your case .

 List<String>  listFromSet = new ArrayList<String>(mPrefsaved.getStringSet("faves", null));

Make sure that your method getStringSet returns a collection of Strings.

like image 135
Suresh Atta Avatar answered Nov 04 '22 22:11

Suresh Atta


Use foreach in stringset and add each string to arraylist

ArrayList<String> arrayList = new ArrayList<String>();
for (String str : stringset)  
    arrayList.add(str);
like image 39
henry4343 Avatar answered Nov 04 '22 21:11

henry4343