Classes and object-oriented in PHP

The difference between classes and objects in PHP programming:
A class is abstract and represents a type of thing.
Object is concrete, a specific instance of a class.
A class is a template for an object, and an object is an individual instance of a class.
Concrete object-oriented examples

<?php  
//这就是一个类(狗类)  
class dog{  
   //属性  
   public $name;  
   public $age;  
   public $color;  
}  
//创建一只狗  
$dog1=new dog();  
//给这只猫赋值.(具体各个)  
$dog1->name="小白";  
$ dog1 ->age=3;  
$ dog 1->color="白色";  
$dog2=new Cat();  
$dog2->name="小花";  
$dog2->age=100;  
$dog2->color="颜色";  
//如果我们找到一只狗,只要找到 $dog1, 那么该变量所有相关的属性都通通的找到  
$findDogName="旺财";  
if($dog2->name==$findDogName){  
       echo $dog2->name."||".$dog2->age."||".$dog2->color;  
}  
?>