CODEWITHSUNDEEP
javaandroidarraylist
cgifox
cgifox

Reputation: 659

Android:ArrayList storing weird values

I just don't understand what's going on here.

ArrayList<ListItem> list=new ArrayList<ListItem>();
ListItem curItem=new ListItem();
String[] contents=cwFile.list();
for(int i=0;i<contents.length;i++){
    curItem.itemName = contents[i];
    if(new File(cwd+contents[i]).isDirectory()){
        curItem.isDir=true;
    }
    list.add(i,curItem);
}
Log.i("Main",list.get(0).itemName);
Log.i("Main",contents[0]);

So in this code snippet, I get the contents of a directory using the File.list() method

Then, I store the names in an ArrayList of ListItem objects, where ListItem is a self-created class.

But, ListItem is just a class that stores the string

class ListItem {
    protected String itemName ="";
    protected boolean isDir=false;
    protected Double size=0.0;
}

However, after logging the first elements of both the array and the ArrayList (last 2 lines of the first code snippet), I get different results!

This is the log output:

03-15 20:29:46.427 465-465/com.harshal.filer I/filer: .userReturn
03-15 20:29:46.427 465-465/com.harshal.filer I/filer: Android

The second output,"Android" is an actual directory on the device. But what's ".userReturn" and where did it come from???

Upvotes: 0

Views: 210

Answers (1)

Frank
Frank

Reputation: 2066

Change your code to the following:

ArrayList<ListItem> list=new ArrayList<ListItem>();
String[] contents=cwFile.list();
for(int i=0;i<contents.length;i++){
    ListItem curItem=new ListItem();
    curItem.itemName = contents[i];
    if(new File(cwd+contents[i]).isDirectory()){
        curItem.isDir=true;
    }
    list.add(i,curItem);
}
Log.i("Main",list.get(0).itemName);
Log.i("Main",contents[0]);

You see I moved 

 ListItem curItem=new ListItem();

into the for-loop. If it's outside the reference of the item at position 0 in the list will always point to the latest entry in your array, thus the weird result.

Upvotes: 2

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