Why am I getting "Class 'app\models\Yii' not found" error?

Question

Model's function for which I got this error:

public function setPassword($password)
{
    $this->password_hash = Yii::$app->security->generatePasswordHash($password);
}

public function generateAuthKey()
{
    $this->auth_key = Yii::$app->security->generateRandomString();
}

Answer 1

Add

use Yii;

Before your class declaration.

Or add a backslash in front of the Yii word.

$this->password_hash = \Yii::$app-> ...