php
// should return: 'Do Androids Dream of Electric Sheep?'
->titleCase('do androids dream of electric SHEEP?', array('do', 'an', 'of'));

php
//should return: 'Rendezvous with Rama'
->titleCase('RENDEZVOUS WITH RAMA', array('With'));

php
// should return: 'Stranger In A Strange Land'
->titleCase('stranger in a strange land');

class StringUtil {
  /**
   * Verify a string of braces
   *
   * Takes a string of braces as a single parameter and determines if the order of the braces is
   * valid.
   *
   * @access public
   * @param String $braces
   * @return Boolean
   * @throws InvalidArgumentException If $braces is not a string
   */
  public function validBraces($braces = '') {
    /**
     * I assume that empty string is valid because
     * is the default value
     * and you have in the test as valid
     */
    if ($braces === '') {
      return true;
    } elseif (empty($braces)) {
      return false;
    }
    /**
     * array of chars allowed,
     * the keys are the open chars
     * the values are the closure
     */
    $symbols = array("(" => ")", "{" => "}", "[" => "]");

    // get array with all characters allowed
    $search = array_merge(array_keys($symbols), array_values($symbols));

    //check valid string
    if (strlen(str_replace($search, '', $braces)) > 0) {
      throw new InvalidArgumentException("ERROR: Invalid Arguments. Just (){}[] characters allowed in the string");
    }

    //check if the length is even
    if (strlen($braces) % 2 !== 0) {
      return false;
    }

    // Make sure start & end chars are not incorrect
    if (in_array(substr($braces, 0, 1), $symbols) || array_key_exists(substr($braces, -1, 1), $symbols)) {
      return false;
    }

    //Make sure the string have the same amount of open & end chars
    foreach ($symbols as $key => $value) {
      if (substr_count($braces, $key) !== substr_count($braces, $value)) {
        return false;
      }
    }

    $bracesArray = str_split($braces);
    for ($i = 0; $i <= count($bracesArray) - 1; $i++) {
      if (in_array($bracesArray[$i], $symbols)) {
        if ($bracesArray[$i] === $symbols[$bracesArray[$i - 1]]) {
          unset($bracesArray[$i], $bracesArray[$i - 1]);
          break;
        } else {
          return false;
        }
      }
    }

    if (!empty($bracesArray)) {
      $newBraces = implode("", $bracesArray);
      return $this->validBraces($newBraces);
    }

    return true;
  }

  /**
   * Convert a string into title case given an optional list of exceptions.
   *
   * @access public
   * @param String $title
   * @param Array $exceptions
   * @return String
   */
  public function titleCase($title, $exceptions = array()) {
    $newExecption = array();
    foreach ($exceptions as $execptionV) {
      $newExecption[] = strtolower($execptionV);
    }
    $stringArray = explode(' ', $title);
    foreach ($stringArray as $key => $value) {
      if (empty($newExecption)) {
        $new[] = ucfirst(strtolower($value));
      } else {
        if ($key == 0) {
          $new[] = ucfirst(strtolower($value));
        } else {
          if (!in_array(strtolower($value), $newExecption)) {
            $new[] = ucfirst(strtolower($value));
          } else {
            $new[] = strtolower($value);
          }
        }
      }
    }
    $newPhrase = implode(" ", $new);
    return $newPhrase;
  }

}

public function validBraces() {
    return array(
        array('()'),
        array('{}'),
        array('[]'),
        array('(){}[]'),
        array('([{}])'),
        array('{}({})[]'),
        array('({})[({})]'),
        array('(({{[[]]}}))'),
        array('')
    );
}


public function invalidBraces() {
    return array(
        array('(}'),
        array('[(])'),
        array('(})'),
        array(')(}{]['),
        array('())({}}{()][]['),
        array('(((({{'),
        array('}}]]))}])')
    );
}

  public function testDefault() {
    $this->assertSame('Abc Def Ghi', $this->util->titleCase('aBC deF Ghi'));
  }

  public function testFirstWord() {
    $this->assertSame('Ab', $this->util->titleCase('ab', array('ab')));
  }

  public function testExceptionWord() {
    $this->assertSame('A bc', $this->util->titleCase('a bc', array('bc')));
  }

  public function testExceptionWordIgnoresCase() {
    $this->assertSame('A bc', $this->util->titleCase('a bc', array('BC')));
  }

  public function testBogusExceptionWords() {
    $this->assertSame('First A Of In', $this->util->titleCase(
                    'First a of in', array('an', 'often', 'into')
    ));
  }

  public function testTitles() {
    $this->assertSame('A Clash of Kings', $this->util->titleCase(
                    'a clash of KINGS', array('a', 'an', 'the', 'OF')
    ));

    $this->assertSame('The quick Brown fox', $this->util->titleCase(
                    'the QUICK bRoWn fOX', array('xyz', 'fox', 'quick', 'the')
    ));
  }