PHP Object-oriented basic concept class and object static property construction/destructor method

1. Traditional process-oriented and modern object-oriented
Traditional process-oriented: refers to the completion of the work is divided into a number of steps to complete one step at a
Modern object-oriented: a task (function) that divides the work that is to be done into one object (functions) each object completes its own task alone
It can be understood as: a cleaning process is a person who finishes the cleaning. Object-oriented is a person sweeping a person to mop the ground
2. Basic object-oriented concepts
Three main features: Package inheritance polymorphism
classes and objects:
Zhang San is an object that Li Si is an object they are all subordinate to the class of people
Class: A concept that describes a certain object with a common characteristic
Object: Refers to a specific object that belongs to a category
Normally, an object cannot be separated from a class, and no object can have a class without a class.
Class human{//Define a category classes is a keyword
//class has some attributes (that is, variables)
var $name = ' Zhang San ';
var $sex = ' Male ';
var $age = ' a ';
//class with some methods (that is, functions)
function Show () {
Echo ' name: '. $this->name. '; Gender: '. $this->sex. '; Age: '. $this->age;
             }
Const PI = 3.14//class has some solid (solid class)
       }  
properties in the class:
definition form (Var is the alias of public):
var $v 1; You can define a value that is not assigned
var $v 2 = 2; Defined simultaneous assignment value cannot be a variable and evaluate an expression
public $v 1;
Public $ = 2;
form of Use:
$ object, property name//property name not preceded by $ symbol
to create an object for the class:
Call
1. Object name = new class name (Human) ();
2. Variable class name
Variable name ($name) = "Class"
Object Name ($lisi) = new variable name ($name) ();
3. Object name = new Self; only internal use of the class refers to itself
function CSelf () {
return new self
}
For example: $lisi = new Human ();
$zhangsan = $lisi->cself ();
The two of them are equal.
4. Object Name 1 = new class name () object Name 2 = new object name 1;
the value of the object:
Value passing: Replication data is independent of each other
Reference passing: Replication is a change of relationship one changes the other
Key Words &;
General Method:
Definition is the same as the use is
Use Also
Access modifiers are not written is public
$this keyword is a pseudo-object that represents the current object of the class that currently belongs
Objects do not display the same content.
system functions:
Gets the class name of an object The result is just a class name string
The result of object name = new class name () Get_class (object name) is the class name
Static properties:
Keyword static
Static $v 1 = 10;
Usage: class:: Attribute name;
static method:
There is no such thing as $this cannot exist.
Construction Method:
Keyword __construct ();
If you don't write, call function ____construct () {
}
Cannot be a static method
Use $this to assign values
destructor Method:
Automatically invoke PHP code execution ends when destroying objects automatically destroy objects available destructors view
You cannot call yourself to perform a physical argument
Manual destruction of unset ($p 1);

PHP Object-oriented basic concept class and object static property construction/destructor method