Convert a {@code string} array into a delimited {@code string} (e.g. CSV).
<p>Useful for {@code toString()} implementations.
@param arr the array to display (potentially {@code null} or empty)
@param delim the delimiter to use (typically a ",")
@return the delimited {@code string}
Convert a {@code string} array into a delimited {@code string} (e.g. CSV). <p>Useful for {@code toString()} implementations. @param arr the array to display (potentially {@code null} or empty) @param delim the delimiter to use (typically a ",") @return the delimited {@code string}