voku / Stringy

    $substringLength = UTF8::strlen($substring, $this->encoding);

    $startOfStr = UTF8::substr($this->str, 0, $substringLength, $this->encoding);

    if (!$caseSensitive) {

      $substring = UTF8::strtolower($substring, $this->encoding);

      $startOfStr = UTF8::strtolower($startOfStr, $this->encoding);

    }

    return (string)$substring === $startOfStr;

  }

        $this->encoding

    );

    if (!$caseSensitive) {

      $substring = UTF8::strtolower($substring, $this->encoding);

      $endOfStr = UTF8::strtolower($endOfStr, $this->encoding);

    }

    return (string)$substring === $endOfStr;

  }