A quick and easy way to join array elements with a separator (the opposite of split) in Java [duplicate]

Answer 1

This small function always comes in handy.

public static String join(String[] strings, int startIndex, String separator) {
    StringBuffer sb = new StringBuffer();
    for (int i=startIndex; i < strings.length; i++) {
        if (i != startIndex) sb.append(separator);
        sb.append(strings[i]);
    }
    return sb.toString();
}

Answer 2

it's in StringUtils:

http://www.java2s.com/Code/JavaAPI/org.apache.commons.lang/StringUtilsjoinObjectarrayStringseparator.htm

Answer 3

public String join(String[] str, String separator){
    String retval = "";
    for (String s: str){ retval+= separator + s;}
    return retval.replaceFirst(separator, "");
}