public function listCurrencies() {
    if (is_null($this->currencyCodes)) {
      $directory = new \RecursiveDirectoryIterator($this->getCurrencyResourceDirectory());
      foreach ($directory as $item) {
        if (preg_match('#^...\.json$#', $item->getFilename())) {
          $this->currencyCodes[] = substr($item->getFilename(), 0, 3);
        }
      }
    }

    return $this->currencyCodes;
  }
public function listCurrencies() {
    if (is_null($this->currencyCodes)) {
      $directory = new \RecursiveDirectoryIterator($this->getCurrencyResourceDirectory());
      foreach ($directory as $item) {
        if (preg_match('#^...\.json$#', $item->getFilename())) {
          $this->currencyCodes[] = substr($item->getFilename(), 0, 3);
        }
      }
    }

    return $this->currencyCodes;
  }
public function listCurrencies ( ) { if ( is_null ( $ this -> currencyCodes ) ) { $ directory = new \ RecursiveDirectoryIterator ( $ this -> getCurrencyResourceDirectory ( ) ) ; foreach ( $ directory as $ item ) { if ( preg_match ( '#^...\.json$#' , $ item -> getFilename ( ) ) ) { $ this -> currencyCodes [ ] = substr ( $ item -> getFilename ( ) , 0 , 3 ) ; } } } return $ this -> currencyCodes ; }
Lists all known currencies.

@return string[]
An array with ISO 4217 currency codes.
Lists all known currencies .