reordering an array

[kellykilbourne]

I'm trying to compare the elements in an string array to an incoming string value. If this method is called, the string value must always be in rs[0] in the new array like so:

rs[0] = "INSERT DT, NPA, NXX";
rs[1] = "EFF DT, NPA, NXX";
rs[2] = "NPA, EFF DT";
rs[3] = "DUMMY SORT 1";

public String[] keepSortBy()
{
try
{
String strCurrSort = "INSERT DT, NPA, NXX";

String[] ds = new String[4];
ds[0] = "EFF DT, NPA, NXX";
ds[1] = "NPA, EFF DT";
ds[2] = "INSERT DT, NPA, NXX";
ds[3] = "DUMMY SORT 1";
String[] rs = new String[ds.length];
for (int i = 0; i < ds.length - 1; i++)
{

if (!ds[i].equals(strCurrSort))
{
rs[0] = strCurrSort;
rs[i + 1] = ds[i];
} else
{
rs[0] = strCurrSort;
rs[i + 1] = ds[i + 1];
}

}
return rs;
} catch (Exception e)
{
System.out.println("Error in keepSortBy: " + e.toString());
return null;
}

}
If the declaration of the ds array is changed to 3 and the appropriate elements are declared ds[0] - ds[2], the above method works every time no matter where the match occurs in the incoming array.

Any suggestions?

Thanks

[emanresu]

the problem is in the line

rs[i + 1] = ds[i];

if both arrays are defined to have 4 elements,
then when i is 3,

rs[i+1] would be invalid because rs only goes from 0 to 3.

that also explains why it works if the size of ds is 3, because i + 1 stays within 0 and 3