# join method

String join ([String separator = "" ])

Converts each element to a String and concatenates the strings.

Iterates through elements of this iterable, converts each one to a String by calling Object.toString, and then concatenates the strings, with the `separator` string interleaved between the elements.

## Implementation

    String join([String separator = ""]) {
      int length = this.length;
      if (!separator.isEmpty) {
        if (length == 0) return "";
        String first = "${elementAt(0)}";
        if (length != this.length) {
          throw new ConcurrentModificationError(this);
        }
        StringBuffer buffer = new StringBuffer(first);
        for (int i = 1; i < length; i++) {
          buffer.write(separator);
          buffer.write(elementAt(i));
          if (length != this.length) {
            throw new ConcurrentModificationError(this);
          }
        }
        return buffer.toString();
      } else {
        StringBuffer buffer = new StringBuffer();
        for (int i = 0; i < length; i++) {
          buffer.write(elementAt(i));
          if (length != this.length) {
            throw new ConcurrentModificationError(this);
          }
        }
        return buffer.toString();
      }
    }