Remove last comma from string that doesn't end with comma in Java 8 [duplicate]

Question

I have input string:

String myString = "test, test1, must not be null";

I want to remove last comma in this string

Expected output:

test, test1 must not be null

Any idea if this can be done using StringUtils?

Answer 1

You can also use a StringBuilder:

String result = new StringBuilder(myString)
    .deleteCharAt(myString.lastIndexOf(",")).toString()

//"test, test1 must not be null" is the result

You may need to wrap that in if(myString.lastIndexOf(",") >= 0) to avoid index out of bounds exceptions

Answer 2

With a regex, you can replace the last , using this for example:

String result = myString.replaceAll(",([^,]*)$", "$1");

In substance, it looks for a comma, followed by 0 or more non comma characters until the end of the string and replaces that sequence with the same thing, without the comma.