How to search for a string in an arraylist

Question

I want to search for a string in an arraylist. My ArrayList contains:

ArrayList <String> list = new ArrayList(); 
list.add("behold");
list.add("bend");
list.add("bet");
list.add("bear");
list.add("beat");
list.add("become");
list.add("begin");

Now I want to search for "bea" and it should return a list containing "bear" and "beat". How can I implement it?

score 31 · Accepted Answer · edited Jan 08 '13 at 13:55

31

 List <String> list = new ArrayList();  
           list.add("behold"); 
           list.add("bend"); 
           list.add("bet"); 
           list.add("bear"); 
           list.add("beat"); 
           list.add("become"); 
           list.add("begin");

           List <String> listClone = new ArrayList<String>(); 
           for (String string : list) {
               if(string.matches("(?i)(bea).*")){
                   listClone.add(string);
               }
           }
        System.out.println(listClone);

edited Jan 08 '13 at 13:55

Community

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1

answered Nov 19 '11 at 08:41

Abhishek

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5

its working, but if list contains Bear, than it does not matches – Romi Nov 19 '11 at 09:30
2

Just you have to change regex, suppose you want match smal 'b' and capital 'B' both then relace "(bea).*" <=> "(b|B)(ea).*". – Abhishek Nov 19 '11 at 18:23
1

There is another way to make above expression case insensitive, use "(?i)(bea).*". – Abhishek Nov 19 '11 at 18:30

score 20 · Answer 2 · answered Nov 19 '11 at 07:42

20

Loop through your list and do a contains or startswith.

ArrayList<String> resList = new ArrayList<String>();
String searchString = "bea";

for (String curVal : list){
  if (curVal.contains(searchString)){
    resList.add(curVal);
  }
}

You can wrap that in a method. The contains checks if its in the list. You could also go for startswith.

answered Nov 19 '11 at 07:42

Udo Held

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Shouldn't **String curVal : list** read: **String curVal resList** and shouldn't you add curVal to the list only if it is NOT currently in the list? – Michael Sims Mar 18 '18 at 14:09

sebnukem · Answer 3 · 2020-09-30T20:52:23.663

17

Nowadays, Java 8 allows for a one-line functional solution that is cleaner, faster, and a whole lot simpler than the accepted solution:

List<String> list = new ArrayList<>();
list.add("behold");
list.add("bend");
list.add("bet");
list.add("bear");
list.add("beat");
list.add("become");
list.add("begin");

List<String> matches = list.stream().filter(it -> it.contains("bea")).collect(Collectors.toList());

System.out.println(matches); // [bear, beat]

And even easier in Kotlin:

val matches = list.filter { it.contains("bea") }

edited Sep 30 '20 at 20:52

answered Aug 26 '16 at 00:13

sebnukem

8,143
6
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2

Stream requires Android Api level > 24. – Adil Soomro Feb 08 '20 at 22:09
Wrong. It requires 24 or greater. ( >= ) – John Lord Jan 17 '21 at 06:38

Marquez · Answer 4 · 2016-07-12T13:19:17.793

9

May be easier using a java.util.HashSet. For example:

  List <String> list = new ArrayList<String>(); 
  list.add("behold");
  list.add("bend");
  list.add("bet");

  //Load the list into a hashSet
  Set<String> set = new HashSet<String>(list);
  if (set.contains("bend"))
  {
    System.out.println("String found!");
  }

edited Jul 12 '16 at 13:19

answered Jul 10 '15 at 21:07

Marquez

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score 8 · Answer 5 · answered Nov 19 '11 at 07:43

8

Since your list doesn't appear to be sorted, you have to iterate over its elements. Apply startsWith() or contains() to each element, and store matches in an auxiliary list. Return the auxiliary list when done.

answered Nov 19 '11 at 07:43

NPE

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score 2 · Answer 6 · answered Nov 19 '11 at 07:52

2

Better way is to use matches() method on every String element of the array. This will help you to search any pattern through regular expressions.

answered Nov 19 '11 at 07:52

Drona

6,886
1
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score 0 · Answer 7 · answered Jul 23 '14 at 06:31

The Best Order I've seen :

// SearchList is your List  
// TEXT is your Search Text
// SubList is your result

                    ArrayList<String> TempList = new ArrayList<String>(
                            (SearchList));
                    int temp = 0;
                    int num = 0;
                    ArrayList<String> SubList = new ArrayList<String>();
                    while (temp > -1) {
                        temp = TempList.indexOf(new Object() {
                            @Override
                            public boolean equals(Object obj) {
                                return obj.toString().startsWith(TEXT);
                            }
                        });
                        if (temp > -1) {
                         SubList.add(SearchList.get(temp + num++));
                         TempList.remove(temp);
                        }
                    }

you can use instead of .StartsWith , .equals or .contains – Hamidreza Sadegh Jul 23 '14 at 06:36 — Hamidreza Sadegh, Jul 23 '14 at 06:36

score 0 · Answer 8 · answered Dec 16 '16 at 12:41

First you have to copy, from AdapterArrayList to tempsearchnewArrayList ( Add ListView items into tempsearchnewArrayList ) , because then only you can compare whether search text is appears in Arraylist or not.

After creating temporary arraylist, add below code.

    searchEditTextBox.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        }
        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
            String txt = charSequence.toString().trim();
            int txtlength = txt.length();
            if (txtlength > 0) {
                AdapterArrayList = new ArrayList<HashMap<String, String>>();
                for (int j = 0; j< tempsearchnewArrayList.size(); j++) {
                    if (tempsearchnewArrayList.get(j).get("type").toLowerCase().contains(txt)) {
                        AdapterArrayList.add(tempsearchnewArrayList.get(j));
                    }
                }
            } else {
                AdapterArrayList = new ArrayList<HashMap<String, String>>();
                AdapterArrayList.addAll(tempsearchnewArrayList);
            }
            adapter1.notifyDataSetChanged();
            if (AdapterArrayList.size() > 0) {
                mainactivitylistview.setAdapter(adapter1);
            } else {
                mainactivitylistview.setAdapter(null);
            }

        }
        @Override
        public void afterTextChanged(Editable editable) {

        }
    });

score 0 · Answer 9 · answered Mar 16 '17 at 13:56

0

List <String> list = new ArrayList();  
           list.add("behold"); 
           list.add("bend"); 
           list.add("bet"); 
           list.add("bear"); 
           list.add("beat"); 
           list.add("become"); 
           list.add("begin");

           List <String> listClone = new ArrayList<String>(); 
           Pattern pattern = Pattern.compile("bea",Pattern.CASE_INSENSITIVE); //incase u r not concerned about upper/lower case
           for (String string : list) {
               if(pattern.matcher(string).find()) {
                   listClone.add(string);
                   continue;
               }
           }
        System.out.println(listClone);

answered Mar 16 '17 at 13:56

Rishabh

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While this code may answer the question, providing additional context regarding how and/or why it solves the problem would improve the answer's long-term value. – morten.c Mar 16 '17 at 14:19
Its pretty simple, i compiled a Pattern object (Pattern.compile("bea",Pattern.CASE_INSENSITIVE)) with 'bea' as my input and i wanted it to ingnore the case of searched pattern.Next i am matching this pattern with all strings in list 1 by 1 and checking if there is atleast 1 match by find() method, if there is any then i am adding matched string into a new list i.e listClone. – Rishabh Mar 17 '17 at 12:40

score 0 · Answer 10 · answered Oct 19 '21 at 22:57

TRY using Google guava library FOR MORE INFO --> https://github.com/google/guava

Iterable<String> result = Iterables.filter(yourListContainStringsYouWantToSearch, Predicates.containsPattern(search));
Log.i("resultsInList", "performSearch:\n"+ Lists.newArrayList(result.iterator()));

score -1 · Answer 11 · answered May 12 '14 at 08:38

import java.util.*;
class ArrayLst
{
    public static void main(String args[])
    {
        ArrayList<String> ar = new ArrayList<String>();
        ar.add("pulak");
        ar.add("sangeeta");
        ar.add("sumit");
System.out.println("Enter the name:");
Scanner scan=new Scanner(System.in);
String st=scan.nextLine();
for(String lst: ar)
{
if(st.contains(lst))
{
System.out.println(st+"is here!");
break;
}
else
{
System.out.println("OOps search can't find!");
break;
}
}
}
}

How to search for a string in an arraylist

11 Answers11

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