how to display string with string count

Question

I am having string array like this:

String[] str = new String[]{"foo","bar","foo","car"}

I need output like this:

bar1car1foo2

I tried like this:

String[] someArray = new String[] { "foo","bar","foo","car"};

            for(int i=0;i<someArray.length;i++){
                int count=0;
                for(int j=0;j<someArray.length;j++){
                    if(someArray[i].equals(someArray[j])){

                        someArray[i] +=count;
                    }
                }
                System.out.println(someArray[i]);
                }

and my output is:

foo0
bar0
foo0
car0

Answer 1

One option is to use Map<String, Integer> where the keys represent the individual strings, and the map value is the counter for each one.

So you can do something like:

Map<String, Integer> stringsWithCount = new TreeMap<>();
for (String item : str) {
  if (stringsWithCount.contains(item)) {
    stringsWithCount.put(item, stringsWithCount.get(item)+1));
  } else {
    stringsWithCount.put(item, 0);
  }
}

And then you can iterate the map when done:

for (Entry<String, Integer> entry : stringsWithCount.entrySet()) {

and build your result string.

That was like the old-school implementation; if you want to be fancy and surprise your teachers, you can go for the Java8/lambda/stream solution:

Arrays.stream(str)
  .collect(Collectors
     .groupingBy(s -> s, TreeMap::new, Collectors.counting()))
  .entrySet()
  .stream()
  .flatMap(e -> Stream.of(e.getKey(), String.valueOf(e.getValue())))
  .collect(Collectors.joining())

But of course, you should be able to explain that piece of code.

Answer 2

    public static void main(String args[]) {

        String[] strArray = new String[] { "foo","bar","foo","car"};
        countduplicate(strArray );
        }


public static void countduplicate(String avalue[]) {
    String str = "";
    Set<String> set = new HashSet<String>();
    for (int i = 0; i < avalue.length; i++) {
        set.add(avalue[i]);
    }
    Iterator<String> iterator = set.iterator();
    List<String> list = new ArrayList<String>();
    while (iterator.hasNext()) {
        int count=0;
        str =iterator.next(); 
        for (int i = 0; i < avalue.length; i++) {
            if(str.equals(avalue[i])){
                count++;
            }
        }
            list.add(str+count);
    }
    for (int i = 0; i < list.size(); i++) {
        System.out.print(list.get(i));
    }
}