Object-Oriented Knowledge-class conversion

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Overview:

To better understand the object-oriented programming thinking, we recommend several common tips to quickly improve object-oriented programming.

1. Farewell To Constants

2. Farewell to variables

3. Farewell to static variables

4. Farewell to Functions

5. Farewell to global variables

6. Farewell to map Array

 

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Tips

 

1. constant conversion to constant type

　　Constant instance:

define("LEVEL_ERROR",‘error‘);define("LEVEL_WARNING",‘warning‘);define("LEVEL_INFO",‘info‘);define("LEVEL_TRACE",‘trace‘);

Common instance:

class Level {    const ERROR = ‘error‘;    const WARNING = ‘warning‘;    const INFO = ‘info‘;    const TRACE = ‘trace‘;}

 

2. convert a variable to an attribute

　　Variable instance:

$ Username = "Zhang San"; $ userage = 18; $ useraddress = "XX Province, XX city, xx Town, XX Village ";

Attribute instance:

class User {    private $name;    private $age;    private $address;    /**     * @param mixed $address     */    public function setAddress($address)    {        $this->address = $address;    }    /**     * @return mixed     */    public function getAddress()    {        return $this->address;    }    /**     * @param mixed $age     */    public function setAge($age)    {        $this->age = $age;    }    /**     * @return mixed     */    public function getAge()    {        return $this->age;    }    /**     * @param mixed $name     */    public function setName($name)    {        $this->name = $name;    }    /**     * @return mixed     */    public function getName()    {        return $this->name;    }    public function __construct($name="",$age=0,$address=""){        $this->name = $name;        $this->age = $age;        $this->address = $address;    }}

$ User = new user ("Zhang San", 18, "XX Province, XX city, xx Town, XX Village ");

 

3. Convert static variables to static attributes

Static variable instance:

static $app;if($app == null){    $app = new App();}

Static attribute instance:

class App {    private static $app = null;    public function instance(){        if(self::$app == null){            self::$app = new self;        }        return self::$app;    }}

 

4. Convert static functions to static functions

Static function instances:

function version(){    return "1.0.0.0";}

Static Method Instance:

class App {    public static function version(){        return "1.0.0.0";    }}

 

5. convert global variables to attributes

Global variable instance:

function login($password){    global $user;    if($user->password === $password){        return true;    }    throw new Exception("invalid password!");}

Attribute instance:

class UserService {    private $user;    /**     * @param mixed $user     */    public function setUser($user)    {        $this->user = $user;    }    /**     * @return mixed     */    public function getUser()    {        return $this->user;    }    public function login($password){        if($this->getUser()->password == $password){            return true;        }        throw new Exception("invalid password!");    }}

 

6. Map array to object

　　Map array instance:

$orderItems = array();function addItem($product,$num,&$orderItems){    $orderItems[] = array("product"=>$product,"num"=>$num);}

Object instance:

class Order {    private $items;    public function addItem($product,$num){        $this->items[] = new OrderItem($product,$num);    }}class OrderItem {    private $product;    private $num;    public function __construct($product,$num){        $this->product = $product;        $this->num = $num;    }}

 

Summary

　　These are some common skills that can be mastered by them. It may be a pleasure for you in your future programming career.

Object-Oriented Knowledge-class conversion