ANDROID: remove duplicates string

Question

I have problem in completely removing the duplicates string in List<String>

String [] myno1 = new String [] {"01", "02", "03", "04", "05", "06",
"07", "08", "09", "10", "11", "12", "13", "14", "15"};

String [] myno = new String [] {"01", "03", "15"};

List<String> stringList = new ArrayList<String>(Arrays.asList(myno));

List<String> stringList1 = new ArrayList<String>(Arrays.asList(myno1));

stringList.addAll(stringList1);

Set<String> set = new HashSet<>(stringList);
stringList.clear();
stringList.addAll(set);

System.out.println("=== s:" +stringList);

but i got this:

=== s:[15, 13, 14, 11, 12, 08, 09, 04, 05, 06, 24, 07, 01, 02, 03, 10]

i want the result to be like this:

=== s:[13, 14, 11, 12, 08, 09, 04, 05, 06, 24, 07, 02, 10]

Can you clarify what exactly you want to do? Do you want to create a list that combines "myno" and "myno1" in such a way that it contains everything except the items contained in both lists (i.e. a xor operation)? — FileNotFoundEx, Jul 28 '19 at 05:40

score 0 · Answer 1 · answered Jul 28 '19 at 05:45

0

As you have to remove the items from another list. HashSet<>() is used to remove the duplicate from the same array list. e.g if the list contains 15 two times and 3 two times then it will remain single time in the list.

Here is the code

foreach(String str : stringList){

stringList1.remove(str);
}

answered Jul 28 '19 at 05:45

Sunny

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It's not what he wants. – Mukit09 Jul 28 '19 at 06:16

score 0 · Accepted Answer · answered Jul 28 '19 at 06:03

Take it:

String[] myno1 = new String[]{"01", "02", "03", "04", "05", "06", "07", 
                              "08", "09", "10", "11", "12", "13", "14", "15"};
String[] myno2 = new String[]{"01", "03", "15"};

// use LinkedHashSet to preserve order
Set<String> set1 = new LinkedHashSet<>(Arrays.asList(myno1));
Set<String> set2 = new LinkedHashSet<>(Arrays.asList(myno2));

// find duplicates
Set<String> intersection = new LinkedHashSet<>();
intersection.addAll(set1);
intersection.retainAll(set2);

// remove duplicates from both sets
Set<String> result = new LinkedHashSet<>();
result.addAll(set1);
result.addAll(set2);
result.removeAll(intersection);

System.out.println("Result: " + result);

Result: [02, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14]

i got it! thank you so much~ :) – twoseven Jul 28 '19 at 07:16 — twoseven, Jul 28 '19 at 07:16

Mukit09 · Answer 3 · 2019-07-28T06:20:03.900

If you use Java 8 or +, you can use this:

String[] myno1 = new String[] { "01", "02", "03", "04", "05", "06", "07", "08", "09", "10", "11", "12", "13", "14", "15" };
String[] myno = new String[] { "01", "03", "15" };
List<String> stringList = new ArrayList<>(Arrays.asList(myno));
List<String> stringList1 = new ArrayList<>(Arrays.asList(myno1));
stringList.addAll(stringList1);

List<String> newList = stringList.stream()
            .filter(string -> Collections.frequency(stringList, string) == 1)
            .collect(Collectors.toList());
System.out.println("=== s:" + newList);

Not needed to change your code that much. Made a new List where no duplicate element inserted. Output is:

=== s:[02, 04, 05, 06, 07, 08, 09, 10, 11, 12, 13, 14]

i got it! thank you so much~ :) – twoseven Jul 28 '19 at 07:16 — twoseven, Jul 28 '19 at 07:16

ANDROID: remove duplicates string

3 Answers3