この奇妙なエラーが発生する理由は何ですか? 「致命的なエラー: 未定義の関数 empty() の呼び出し」
function newpart($name,$country,$bday_day,$bday_month,$bday_year,$gender,$pass1,$pass2,$email,$option1,$secondOption1,$secondOptionLevel1){
$this->name = $name;
$this->country = $country;
$this->bday_day = $bday_day;
$this->bday_month = $bday_month;
$this->bday_year = $bday_year;
$this->gender = $gender;
$this->pass1 = $pass1;
$this->pass2 = $pass2;
$this->email = $email;
$this->option1 = $option1;
$this->secondOption1 = $secondOption1;
$this->secondOptionLevel1 = $secondOptionLevel1;
if( empty($this->name) || empty($this->pass1) ){
$this->errorCount++;
}
}