Possible Duplicate:
convert String arraylist to string array in java?
Following is my code
ArrayList<String> IdList = new ArrayList<String>();
and I want to copy items from
IDList to int IdArray[].
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int[] or String[] array?Prince John Wesley– Prince John Wesley2011-10-14 09:05:45 +00:00Commented Oct 14, 2011 at 9:05
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Actually i want it int array. but String[] is also fine.Soniya– Soniya2011-10-14 09:06:49 +00:00Commented Oct 14, 2011 at 9:06
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You should start with an ArrayList<int> in the first place if it doesn't matter XDRob– Rob2011-10-14 09:08:57 +00:00Commented Oct 14, 2011 at 9:08
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@ All: Thanks for your help. Following code helped me out String[] array = Idlist.toArray(new String[list.size()]);Soniya– Soniya2011-10-14 10:08:32 +00:00Commented Oct 14, 2011 at 10:08
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6 Answers
Try this stuff,
int arr[] = new int[arrList.size()];
for (int i = 0; i < arrList.size(); i++) {
arr[i] = Integer.parseInt(arrList.get(i));
}
3 Comments
Soniya
gave ArrayIndexOutOfBoundException
Soniya
int asize= IdList.size(); int arr[] = new int[asize]; for (int i = 0; i < asize); i++) { arr[i] = Integer.parseInt(IdList.get(i)); }
Soniya
ArrayList<String> IdList = new ArrayList<String>();
int IdArray[].
for (int i = 0; i < IdList.size(); i++) {
IdArray[i] = (int)IdList.get(i));
}
Comments
I think you must iterate through all items, which are Strings, and parse each of them into an int to populate your new int[] array.
1 Comment
Soniya
Did you mean, Iterator itr = IdList.iterator(); int IdArray[]={}; int d=0; while(itr.hasNext()) { String topic_id = (String) itr.next(); IdArray[d]= Integer.parseInt(topic_id); d++; System.out.print("============"+topic_id ); }
// String array
String[] arr = idList.toArray(new String[0]);
// for int array
int[] iarr = new int[arr.length];
int idx = 0;
for(String s : arr) {
iarr[idx++] = Integer.parseInt(s);
}
answered Oct 14, 2011 at 9:08
Prince John Wesley
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Comments
String [] outStrArray = (String [])IdList.toArray()
1 Comment
x4u
This will throw a ClassCastException because
Collection.toArray() returns a Object[].int[] IdArray = IdList.toArray();
However, this will probably fail because you're trying to convert a string-arraylist to an int-array..
