Collecting String Elements from an array and grouping them together into another string array?

I have an array which consists of a group of string elements. I want to collect a group of elements, as shown in my code below, and place group of these elements in a new element of another array.

Consider the array I want to collect values from is something like ".", "-", ".",

The program I am writing decodes Morse code, not that it matters, it just means that the array will have recurring values in random orders:

for (int n = 0; n < 100; n++)
{
    if ((didah[n] == ".") || (didah[n] == "-"))
    {
        currentDidah = n;
        //cout <<"first didah" <<currentDidah<<endl;
    }
    if ((didah[n]== "." || (didah[n]=="-") && (didah[n+1] == " ")  && (didah[n+2] == " " )) ) 
    {
        lastDidah = n;
        //cout <<"last didah" <<lastDidah;
    }
    while ((n>=currentDidah) && (n<lastDidah))
    {// most likely infinite
        valInBet += didah[n];
        cout << valInBet << "WORKING"<< endl;
        collection[n] = valInBet;
    }

I have determined when to collect the values and when to stop. The main problem I know is the while loop, the logic behind it is not correct because last didah is always bigger than "n" (for loop counter).

All help appreciated, thanks in advance :)