Java Utililty Methods Array Join

Joins the elements of the provided array into a single String containing the provided list of elements.

No delimiter is added before or after the list.

if (array == null) {
    return null;
return join(array, separator, 0, array.length);

String result = null;
for (String str : array) {
    result = (result == null ? "" : result + separator) + str;
return result;

final int len = arrays.length;
if (arrays == null || len == 0) {
    return "";
StringBuilder sb = new StringBuilder();
for (int i = 0; i < len; i++) {
    sb.append(arrays[i]);
    if (seperator != null && (i < len - 1)) {
...

return join(Arrays.asList(in), sep);

return Arrays.asList(strings).toString();

final StringBuffer buffer = new StringBuffer();
if (strings != null && strings.length > 0) {
    buffer.append(strings[0]);
    for (int i = 1; i < strings.length; i++) {
        buffer.append(joinString);
        buffer.append(strings[i]);
return buffer.toString();

if (values == null) {
    return "";
final StringBuilder result = new StringBuilder(values.length * AVERAGE_STRING_LENGTH);
for (int i = 0; i < values.length; i++) {
    result.append(values[i]);
    if (i < values.length - 1) {
        result.append(delimiter);
...

return join(array, String.valueOf(c));

return join(Arrays.asList(collection));

if (array != null) {
    StringBuilder buf = new StringBuilder(Math.max(16, (separator.length() + 1) * array.length));
    char singleChar = separator.length() == 1 ? separator.charAt(0) : 0;
    for (int i = 0; i < array.length; i++) {
        if (i != 0) {
            if (singleChar != 0) {
                buf.append(singleChar);
            } else {
...