How to convert arrayList to string separated by hyphen

Question

I have String ArrayList has some elements but I need to convert it to string each element is separated from other by - this is the arrayList

List<String> items = new ArrayList<String>();
items.add("a");
items.add("b");
items.add("c");
:
:

I need to get the string like this

"a-b-c-..."

Create a `StringBuilder` object and use `append` to attached each string, then convert the StringBuilder to a String. Use `StringBuffer` instead of `StringBuilder` if code is synchronized. — Al Lelopath, May 06 '16 at 15:35
sure on java . but I have told you about php this problem sove by implode("-",array); and I am looking for like this in java please see the accepted answer. any way I appreciated your help — Naham Soft, May 06 '16 at 15:56

Shadow · Accepted Answer · 2016-05-09T23:29:25.970

18

If you are using Java 8 you can use the join function of the String class:

String result = String.join("-", items);

If you are programming for Android, Java 8 is not available. You can instead use:

String result = TextUtils.join("-", items);

edited May 09 '16 at 23:29

answered May 06 '16 at 15:44

Shadow

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Learn something new about java 8 everyday. Thanks! – Rabbit Guy May 06 '16 at 15:46
Oooh fancy. This is a great tip. – Tom Mac May 06 '16 at 15:47
wow this is a great way thanks so much – Naham Soft May 06 '16 at 16:02
hey bro. this method does not work. can not resolve method join – Naham Soft May 06 '16 at 17:20
1

@NahamSoft are you using Java 8? – Shadow May 06 '16 at 17:26
@Shadow ( version 8 update 25 ( build 1.8.0_25-b18) – Naham Soft May 07 '16 at 14:07
@NahamSoft are you by chance doing this on Android? – Shadow May 07 '16 at 15:13
@Shadow I do not understand what did you mean. – Naham Soft May 07 '16 at 16:01
@NahamSoft Mobile Phone Development, or PC? – Shadow May 07 '16 at 16:27
@Shadow Mobile phone. but I am sorry bro how can I know whats java am I using? – Naham Soft May 07 '16 at 17:56
@Shadow how can I know what java I am using in android studio – Naham Soft May 07 '16 at 20:20
1

@NahamSoft in Mobile you can't use Java 8. Instead of `String.join("-", items)` you will need to use `TextUtils.join("-", items)` – Shadow May 08 '16 at 05:23
it works fine now thanks so much bro – Naham Soft May 09 '16 at 18:18
It saved much of my time. Thank you so much! – hetsgandhi Feb 19 '19 at 11:27

score 5 · Answer 2 · answered May 06 '16 at 15:44

5

One line:

String allItems = String.join("-", items);

Documentation is here.

answered May 06 '16 at 15:44

VGR

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thanks so much bor. this is what am I looking for – Naham Soft May 06 '16 at 16:04

score 2 · Answer 3 · answered May 06 '16 at 15:35

2

You can use Joiner from google-guava:

List<String> items = new ArrayList<String>();
items.add("a");
items.add("b");
items.add("c");

String result = Joiner.on("-").join(items);

here is the link - https://github.com/google/guava/wiki/StringsExplained#joiner

answered May 06 '16 at 15:35

Oleg Khalidov

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This is a nice one liner, but probably a bit overkill if they aren't already using guava – Andrew Brooke May 06 '16 at 15:43
Well, good time to start using it) – Oleg Khalidov May 06 '16 at 15:46
I am looking for method like implode in php and this is what I am looking for.thanks so much. this is the accepted answer. good luck bro – Naham Soft May 06 '16 at 15:49
1

@NahamSoft You can find such functionality in pure Java 8 without using 3rd party libraries (Guava) so if you are using Java 8 it will be better to accept the other answer which has already couple of upvotes. – ctomek May 06 '16 at 15:51
@ctomek do know another function is better ? what is it ? . and thanks for your help – Naham Soft May 06 '16 at 15:59
@NahamSoft See an answer from Shadow. – ctomek May 06 '16 at 16:01
@ctomek thanks for your attention. I had not see it then.I have edit the accepted answer – Naham Soft May 06 '16 at 16:07
@KhalidovOleg how can I know what java I am using in android studio ? – Naham Soft May 07 '16 at 20:46
@NahamSoft it's in the settings. Anyway, it cannot be `java-8` due to android doesn't support it yes. So `google-guava` is the way you can handle your question – Oleg Khalidov May 07 '16 at 20:51

score 2 · Answer 4 · answered May 06 '16 at 15:47

No guava libs will be possible by manipulating the toString result

public static void main(String[] args) {
        List<String> items = new ArrayList<String>();
        items.add("a");
        items.add("b");
        items.add("c");
        System.out.println(items.toString().replace(", ", "-"));
        // no [ ] 
        System.out.println(items.toString().substring(1, items.toString().length() - 1).replace(", ", "-"));
    }

score 1 · Answer 5 · answered May 06 '16 at 15:52

    List<String> items = new ArrayList<String>();
    items.add("a");
    items.add("b");
    items.add("c");
    StringBuilder builder = new StringBuilder();
    builder.append(items.get(0));
    for (int i = 1; i < items.size(); i++) {
        builder.append("-").append(items.get(i));
    }
    String result = builder.toString();
    System.out.println(""+ result);

score 0 · Answer 6 · answered May 06 '16 at 15:42

0

  StringBuilder builder = new StringBuilder();
    builder.append(items.get(0));
    for (int i = 1; i < items.size(); i++) {
        builder.append("-").append(items.get(i));
    }
    String result = builder.toString();

answered May 06 '16 at 15:42

Lina Shyshova

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its ok like this.but is there a method like implode in php – Naham Soft May 06 '16 at 15:45
please see the accepted answer. any way I appreciated your help – Naham Soft May 06 '16 at 15:51

score 0 · Answer 7 · answered May 06 '16 at 15:44

0

You can create a simple function for this

List<String> items = new ArrayList<String>();
items.add("a");
items.add("b");
items.add("c");

Log.d("myFormattedList",getFormattedString(items));

private String getFormattedString() {
    String tempString = "";
    for (String temp: items) {
        tempString += temp;
    }
    tempString.substring(0,str.length()-1); //remove last char "-"
    return tempString;
}

answered May 06 '16 at 15:44

Emin Ayar

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please see the accepted answer. any way I appreciated your help – Naham Soft May 06 '16 at 16:08

How to convert arrayList to string separated by hyphen

7 Answers7