카타 8급 Parse nice int from char problem

1 C

int getAge(const char *inputString) {
    return *inputString - 48;
}

int getAge(const char *inputString) {
    return *inputString - '0';
}

int getAge(const char *inputString) {
    return inputString[0] -'0';
}

2 PHP

function getAge($response) :int {
  return intval($response);
}

function getAge($response) :int {
  return (int) $r;
}

function getAge($response) {
  return 0+$response;
}

function getAge($response) {
  return 1*$response;
}

function getAge($response) {
  return +$response;
}

function getAge($response) {
  return (int)$response{0};
}

function getAge($response) {
  return $response[0];
}

function getAge($response) {
  return number_format($response);
}