PHP致命错误：在非对象中调用成员函数getScore（）

Question

this is my first question

I Have following class

class ProDetection {
public function ProDetection ( ) { }
public function detect($word) {
    ............
}
public function getScore() {
    return $score;
}
}

class SaveDetection {
public function SaveDetection($words) {
    $proDetection = new ProDetection();
    for($i=0;$i<sizeof($words);$i++) {
        $proDetection->detect($words[$i]);
    }
}
public function getScore() {
    return $this->proDetection->getScore();\\line 22
}
}

in other PHP file, i'm try to calling SaveDetection to getScore();

$konten = "xxxx xxxx xxx";
$save = new SaveDetection($konten);
print_r( $save->getScore() );

But i got an error message

Notice: Undefined property: SaveDetection::$proDetection in C:\xampp\htdocs\inovasi\SaveDetection.php on line 22

Fatal error: Call to a member function getScore() on a non-object in C:\xampp\htdocs\inovasi\SaveDetection.php on line 22

Please need your help

Answer 1

Try this. Declare your variables as private (Coz if your code grows, it is hard to find what all the object or variables are used in the class.)

class SaveDetection {
    private $proDetection = null;
    public function __construct($words) {
        $this->proDetection = new ProDetection();
        for($i=0;$i<sizeof($words);$i++) {
            $this->proDetection->detect($words[$i]);
        }
    }
    public function getScore() {
        return $this->proDetection->getScore();\\line 22
    }

    private $proDetection;

}