Question

I have to compare a master array with a child array and tag the master array with a certain text (say “#”) for the common ones –

MasterArray = {"A", "B", "C", "D", "E"}
ChildArray = {"A", "C"}

OutputArray = {"A#", "B", "C#", "D", "E"}

The output will be displayed directly to JList. I am using it here to explain the requirement.

What should I use to get the same output…?

Answer 1

Convert your arrays to ArrayLists using Arrays.asList to make them easier to work with. Then iterate over your master array and check if the child array contains each element using the ArrayList.contains method. If it does, append ‘#’ to the element. Here is some sample code to help you:

String[] master = { "A", "B", "C", "D", "E" };
String[] child = { "A", "C" };

//convert to lists
List<String> masterList = Arrays.asList(master);
List<String> childList = Arrays.asList(child);

//iterate over the master
for (int i = 0; i < masterList.size(); i++) {
    String m = masterList.get(i);

    //check child contains the master element
    if (childList.contains(m)) {
        //append #
        masterList.set(i, m + '#');
    }
}

//convert to array and create a jList
JList jlist = new JList(masterList.toArray());