Getting values from parent class to child class from an instance - php

I have a person class with a $name property and an officer class with an $officer_name property. I need to be able to get the $name property from the person class to the officer class. In this case it should have an output of "Major Blake". Do I need to make an instance of the officer class for me to be able to echo this out?
class person {
protected $name;
private function set_name($fv_name) {
$this->name = $fv_name;
}
public function get_name() {
return $this->name;
}
function __construct($fv_name) {
$this->set_name($fv_name);
}
}
class officer extends person {
private function give_rank(){
return "Major ";
}
function __construct() {
echo $officer_name = $this->give_rank() . parent::get_name();
}
}
$iv_person = new person("Blake");

Please try this code :
your class :
<?php
class person {
protected $name;
private function set_name($fv_name) {
$this->name = $fv_name;
}
public function get_name() {
return $this->name;
}
function __construct($fv_name) {
$this->set_name($fv_name);
}
}
class officer extends person {
private function give_rank(){
return "Major ";
}
function __construct($fv_name) {
parent::__construct($fv_name);
}
function output(){
return $this->give_rank().parent::get_name();
}
}
your call :
$iv_person = new officer("Blake");
echo $iv_person->output();

Related

Fatal error after declaring function abstract

I have a problem with an error I am getting that says:
Class Car contains 1 abstract method and must therefore be decla
red abstract or implement the remaining methods (Car::accelerate) in C:\xampp
\htdocs\php\learn_php_oop\Car.php on line 58.
This is the code in two files I am using:
Car.php
<?php
/**
* represents generic properties and methods for any type of car
*/
class Car
{
protected $colour, $doorNumber, $fuelType, $rightHandDrive, $accelerate;
public function __construct($rightHandDrive = true)
{
$this->rightHandDrive = $rightHandDrive;
}
public function getColour()
{
return $this->colour;
}
public function setColour($colour)
{
$this->colour = $colour;
}
public function getDoorNumber()
{
return $this->doorNumber;
}
public function setDoorNumber($doorNumber)
{
$this->doorNumber = $doorNumber;
}
public function getFuelType()
{
return $this->fuelType;
}
public function setFuelType($fuelType)
{
$this->fuelType = $fuelType;
}
public function getRightHandDrive()
{
return $this->rightHandDrive;
}
public function setRightHandDrive($rightHandDrive)
{
$this->rightHandDrive = $rightHandDrive;
}
abstract protected function accelerate();
}
?>
Sport_car.php
<?php
include ('Car.php');
/**
* represents sport cars
*/
class Sport_car extends Car
{
public function accelerate()
{
$this->accelerate = 5;
}
}
?>
I have spent some time trying to figure out why this is happening but I just do not know why? Please help.
It's an OOP problem, in your case you must declare your Car Object as Abstract like this :
<?php
/**
* represents generic properties and methods for any type of car
*/
abstract class Car
{
protected $colour, $doorNumber, $fuelType, $rightHandDrive, $accelerate;
public function __construct($rightHandDrive = true)
{
$this->rightHandDrive = $rightHandDrive;
}
public function getColour()
{
return $this->colour;
}
public function setColour($colour)
{
$this->colour = $colour;
}
public function getDoorNumber()
{
return $this->doorNumber;
}
public function setDoorNumber($doorNumber)
{
$this->doorNumber = $doorNumber;
}
public function getFuelType()
{
return $this->fuelType;
}
public function setFuelType($fuelType)
{
$this->fuelType = $fuelType;
}
public function getRightHandDrive()
{
return $this->rightHandDrive;
}
public function setRightHandDrive($rightHandDrive)
{
$this->rightHandDrive = $rightHandDrive;
}
abstract protected function accelerate();
}
?>
Explanations :
A class wich is extended with at least one abstract method in it has to be defined as abstract itself, otherwise you'll get an error

PHP : How to call method from other class without inheritance

I have a little problem here, sorry if asking a dumb question.
so, I have StoreCategories Class which have :
class StoreCategories
{
private $store_category_id;
private $category;
public function setStoreCategoryId($store_category_id)
{
$this->store_category_id = $store_category_id;
}
public function getStoreCategoryId()
{
return $this->store_category_id;
}
public function setCategory($category)
{
$this->category = $category;
}
public function getCategory()
{
return $this->category;
}
}
In my index.php I declare the object like this :
$types = array();
while($stmt->fetch())
{
$type = new StoreCategories();
$type->setCardId($card_id);
$type->setStoreCategoryId($store_category_id);
$type->setCategory($category);
array_push($types, $type);
}
As you see, I want to set Card ID which is not in the StoreCategories Class..
I have a Card Class like this :
class Card
{
private $card_id;
public function setCardId($card_id)
{
$this->card_id = $card_id;
}
public function getCardId()
{
return $this->card_id;
}
}
I know I can user Class Card extends StoreCategories to get the Card ID, but it's too much risk..
Anyone have the other ways to do it ?
Thanks :)
You can use Traits
Move common part of the code into new trait:
trait CardIdTrait {
private $card_id;
public function setCardId($card_id)
{
$this->card_id = $card_id;
}
public function getCardId()
{
return $this->card_id;
}
}
And modify Card class to:
class Card {
use CardIdTrait;
}
and
class StoreCategories
{
use CardIdTrait;
private $store_category_id;
private $category;
// ...
}

How get method from another class method

I have two class es
class Pet {
public $pet = null;
public function setPet(){}
public function getPet(){}
}
and
class B {
public $cat = 'cat';
public $dog = 'bog';
public function cat()
{
$pet = new Pet();
$pet->pet = $this->cat;
}
public function dog()
{
$pet = new Pet();
$pet->pet= $this->dog;
}
}
Can I get this:
$pet = new Pet();
$pet->setPet()->dog();
$pet->getPet(); //dog
I don't believe you can. You could make class B extends Pet. That will allow you to call the functions from the class Pet. Read up on object inheritance, that might help! http://php.net/manual/en/language.oop5.inheritance.php
You can simply extend Class Pet on Class B to call functions from the Pet class. So Class B inherits the functions of Pet.
Class B extends Pet {
// class B functions here...
}
I laughed while I'm writing down my code here..
<?php
class Pet {
public $name;
public function setName($string) {
$this->name = $string;
}
public function getName() {
return $this->name;
}
}
class Dog extends Pet {
public function bark() {
echo "Arf arf!";
}
}
class Cat extends Pet {
public function meow() {
echo "Meoooww~ purrr~";
}
}
$dog = new Dog();
$dog->setName("Jacob");
$dog->bark(); //Arf arf!
echo "Good job, ".$dog->getName()."!"; //Good job, Jacob!
?>
sir you cant call $pet->setPet()->dog() with ->dog() since setPet() is a function and not an object.. just like they said, the right thing to do with your code is to extend it as a super class and declare a Dog Class as the child class..
My variant
class Pet {
public $pet = null;
public function setPet($pet = null)
{
if (is_null($pet)) {
return new B($this);
} else {
$this->pet = $pet;
return $this;
}
}
public function getPet()
{
return $this->pet;
}
}
class B {
protected $pet = null;
protected $cat = 'cat';
protected $dog = 'bog';
public function __construct(Pet $pet)
{
$this->pet = $pet;
}
public function cat()
{
$this->pet->setPet($this->cat);
return $this->pet;
}
public function dog()
{
$this->pet->setPet($this->dog);
return $this->pet;
}
}
$pet = new Pet();
$pet->setPet()->cat();
var_dump($pet->getPet());

Use method of parent class when extending

Probably a silly question.. but how do I correctly use the methods of class Test in class Testb without overriding them?
<?php
class Test {
private $name;
public function __construct($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
}
<?php
class Testb extends Test {
public function __construct() {
parent::__construct($name);
}
}
<?php
include('test.php');
include('testb.php');
$a = new Test('John');
$b = new Testb('Batman');
echo $b->getName();
You need to give the Testb constructor a $name parameter too if you want to be able to initialize it with that argument. I modified your Testb class so that its constructor actually takes an argument. The way you currently have it, you should not be able to initialize your Testb class. I use the code as follows:
<?php
class Test {
private $name;
public function __construct($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
}
class Testb extends Test {
// I added the $name parameter to this constructor as well
// before it was blank.
public function __construct($name) {
parent::__construct($name);
}
}
$a = new Test('John');
$b = new Testb('Batman');
echo $a->getName();
echo $b->getName();
?>
Perhaps you do not have error reporting enabled? In any event, you can verify my results here: http://ideone.com/MHP2oX

Get data from object composition

Let's say I have 3 objects : "Place", "Person", "Action".
Depending on the place where is the person and the age of this person, this person can do different action.
For example :
$place->person->action->drive(); // OK if place is "parking" and "person" is 18+
$place->person->action->learn(); // OK if the place is "school" and person is less than 18.
How can I access the data about the objects "Person" and "Place" from the Action class ?
Classes examples :
class Place {
public $person;
private $name;
function __construct($place, $person) {
$this->name = $place;
$this->person = $person;
}
}
class Person {
public $action;
private $name;
private $age;
function __construct($name, $age) {
$this->name = $name;
$this->age = $age;
$this->action = new Action();
}
}
class Action {
public function drive() {
// How can I access the person's Age ?
// How can I acess the place Name ?
}
public function learn() {
// ... Same problem.
}
}
I think I could transmit "$this" from Person to Action when I create the Action Object (ie. $this->action = new Action($this)), but what about the Place data ?
It doesn't make sense to make Person a property of Place nor Action a property of Person.
I'd be more inclined to create public getters for Person and Place's properties and either make them injectable properties of Action or at least pass them as arguments to Action's methods, eg
class Place
{
private $name;
public function __construct($name)
{
$this->name = $name;
}
public function getName()
{
return $this->name;
}
}
class Person
{
private $name;
private $age;
public function __construct($name, $age)
{
$this->name = $name;
$this->age = $age;
}
public function getName()
{
return $this->name;
}
public function getAge()
{
return $this->age();
}
}
class Action
{
private $person;
private $place;
public function __constuct(Person $person, Place $place)
{
$this->person = $person;
$this->place = $place;
}
public function drive()
{
if ($this->person->getAge() < 18) {
throw new Exception('Too young to drive!');
}
if ($this->place->getName() != 'parking') {
throw new Exception("Not parking, can't drive!");
}
// start driving
}
}

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