Getting Uncaught Error: Call to undefined method Vehicles::setPassengerSeats()

Question

我收到这个错误：

uncaught error call to undefine method Vehicles::setPassengerSeats() in C:\xampp\htdocs\practice\vehicle.php:91.

我也添加了错误的截图。请检查并告诉我如何解决？我想我的子 class 有问题，但我不知道在哪里？

这是我的源代码：

<?php  

class Vehicles{
    private $noOfVehicles;
    private $color;
    private $fuel;
    private $speed;

    public function getNoOfVehicles(){
        return $this->noOfMobiles;
    }

    public function setNoOfVehicles($Vehicles){
        $this->noOfMobiles = $Vehicles;
        echo "No of Vehicles are: ".$this->noOfVehicles."</br>";
    }

    public function getColor(){
        return $this->color;
    }

    public function setColor($look){
        $this->color = $look;
        echo "</br>The Color of Vehicle is: ".$this->color."</br>";
    }

    public function getFuel(){
        return $this->fuel;
    }

    public function setFuel($petrol){
        $this->fuel = $petrol;
        echo "</br>The fuel is: ".$this->color."</br>";
    }

    public function getSpeed(){
        return $this->speed;
    }

    public function setSpeed($vehicleSpeed){
        $this->speed = $vehicleSpeed;
        echo "</br>The speed of vehicle is: ".$this->speed."</br>";
    }

}

class PassengerVehicles extends Vehicles{
    private $passengerSeats;

    public function getPassengerSeats(){
        return $this->passengerSeats;
    }

    public function setPassengerSeats($seats){
        return $this->passengerSeats = $seats;
        echo "</br>Passenger Seats are: ".$this->passengerSeats."</br>";
    }

}

class TransportationVehicles extends Vehicles{
    private $noOfDoors;
    private $loadCapacity;

    public function getNoOfDoors(){
        return $this->noOfDoors;
    }

    public function setNoOfDoors($doors){
        return $this->noOfDoors = $doors;
        echo "</br>The No of Doors are: ".$this->noOfDoors."</br>";
    }

    public function getLoadCapacity(){
        return $this->loadCapacity;
    }

    public function setLoadCapacity($capacity){
        return $this->loadCapacity = $capacity;
        echo "The Load Capacity is: ".$this->loadCapacity."</br>";
    }
}

$VehiclesObj = new Vehicles;
$VehiclesObj->setNoOfVehicles("15");
$VehiclesObj->setColor("Black");
$VehiclesObj->setFuel("5 Litre");
$VehiclesObj->setSpeed("120 km/h");

$VehiclesObj->setPassengerSeats("4");
$VehiclesObj->setNoOfDoors("4");
$VehiclesObj->setLoadCapacity("500 KG");

?>

Answer 1

您不能从 parent 调用 child 方法。您需要创建 child 的实例才能调用 parent 方法

   class Vehicles{
    private $noOfVehicles;
    private $color;
    private $fuel;
    private $speed;

    public function getNoOfVehicles(){
        return $this->noOfMobiles;
    }

    public function setNoOfVehicles($Vehicles){
        $this->noOfMobiles = $Vehicles;
        echo "No of Vehicles are: ".$this->noOfVehicles."</br>";
    }

    public function getColor(){
        return $this->color;
    }

    public function setColor($look){
        $this->color = $look;
        echo "</br>The Color of Vehicle is: ".$this->color."</br>";
    }

    public function getFuel(){
        return $this->fuel;
    }

    public function setFuel($petrol){
        $this->fuel = $petrol;
        echo "</br>The fuel is: ".$this->color."</br>";
    }

    public function getSpeed(){
        return $this->speed;
    }

    public function setSpeed($vehicleSpeed){
        $this->speed = $vehicleSpeed;
        echo "</br>The speed of vehicle is: ".$this->speed."</br>";
    }

}

class PassengerVehicles extends Vehicles{
    private $passengerSeats;

    public function getPassengerSeats(){
        return $this->passengerSeats;
    }

    public function setPassengerSeats($seats){
        return $this->passengerSeats = $seats;
        echo "</br>Passenger Seats are: ".$this->passengerSeats."</br>";
    }

}

class TransportationVehicles extends Vehicles{
    private $noOfDoors;
    private $loadCapacity;

    public function getNoOfDoors(){
        return $this->noOfDoors;
    }

    public function setNoOfDoors($doors){
        $this->noOfDoors = $doors;
        echo "</br>The No of Doors are: {$this->noOfDoors}</br>";

        return $this->noOfDoors;
    }

    public function getLoadCapacity(){
        return $this->loadCapacity;
    }

    public function setLoadCapacity($capacity){
        return $this->loadCapacity = $capacity;
        echo "The Load Capacity is: ".$this->loadCapacity."</br>";
    }
}

$truck = new TransportationVehicles();
$truck->setNoOfVehicles("15");
$truck->setColor("Black");
$truck->setFuel("5 Litre");
$truck->setSpeed("120 km/h");
$truck->setNoOfDoors("4");
$truck->setLoadCapacity("500 KG");

$taxi = (new PassengerVehicles())->setPassengerSeats('4');

在这种情况下，您将拥有 Vehicles class + 自己的两个实例 child。

第一个实例与车辆本身 + 运输属性有关，例如 $noOfDoors 和 $loadCapacity - 例如卡车。第二个是载客车辆的实例 - 例如出租车。

并且您试图让乘客选择从公共汽车乘坐出租车。

Answer 2

您调用了另一个 class 中的方法 setPassengerSeats 而不是 Vehicles 您应该先创建实例，然后调用此方法：

$passangerVehicle = new PassengerVehicles;
$passangerVehicle->setPassengerSeats("4");

Getting Uncaught Error: Call to undefined method Vehicles::setPassengerSeats()

Getting Uncaught Error: Call to undefined method Vehicles::setPassengerSeats()

php

php-7