Remove trailing comma from comma-separated string

Question

I got String from the database which have multiple commas (,) . I want to remove the last comma but I can\'t really find a simple way of doing it.

Answer 1

To remove the ", " part which is immediately followed by end of string, you can do:

str = str.replaceAll(", $", "");

This handles the empty list (empty string) gracefully, as opposed to lastIndexOf / substring solutions which requires special treatment of such case.

Example code:

String str = "kushalhs, mayurvm, narendrabz, ";
str = str.replaceAll(", $", "");
System.out.println(str);  // prints "kushalhs, mayurvm, narendrabz"

---

NOTE: Since there has been some comments and suggested edits about the ", $" part: The expression should match the trailing part that you want to remove.

• If your input looks like "a,b,c,", use ",$".
• If your input looks like "a, b, c, ", use ", $".
• If your input looks like "a , b , c , ", use " , $".

I think you get the point.

Answer 2

You can do something like this using 'Java 8'

private static void appendNamesWithComma() {
    List<String> namesList = Arrays.asList("test1", "tester2", "testers3", "t4");
    System.out.println(namesList.stream()
                                .collect(Collectors.joining(", ")));

}

Answer 3

I'm late on this thread but hope it will help to some one.......

String abc = "kushalhs , mayurvm , narendrabz ,";

if(abc.indexOf(",") != -1){
    abc = abc.substring(0,abc.length() - 1);
}

Answer 4

Check if str.charAt(str.length() -1) == ','. Then do str = str.substring(0, str.length()-1)

Answer 5

(^(\s*?\,+)+\s?)|(^\s+)|(\s+$)|((\s*?\,+)+\s?$)

Regexr

ex:

a, b, c
, ,a, b, c, 
,a, b, c   ,
,,a, b, c, ,,,
, a, b, c,    ,
    a, b, c     
     a, b, c ,,
, a, b, c, 
, ,a, b, c, ,
 , a, b, c , 
,,, a, b, c,,, 
,,, ,,,a, b, c,,, ,,,
,,, ,,, a, b, c,,, ,,,
 ,,,a, b, c ,,,
 ,,,a, b, c,,, 
   a, b, c   

becomes:

a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c
a, b, c

Answer 6

i am sharing code form my project using regular expression you can do this...

String ChildBelowList = "";

    if (!Childbelow.isEmpty()) {
        for (int iCB = 0; iCB < Childbelow.size(); iCB++) {

            ChildBelowList = ChildBelowList += Childbelow.get(iCB) + ",";



        }
        ChildBelowList = ChildBelowList.replaceAll("(^(\\s*?\\,+)+\\s?)|(^\\s+)|(\\s+$)|((\\s*?\\,+)+\\s?$)", "");

        tv_childbelow.setText(ChildBelowList);

    } else {
        ll_childbelow.setVisibility(View.GONE);
    }