An analysis of PHP object-oriented public private protected access modifiers _php tips

There are three types of access modifiers in PHP, respectively:
Public (common, default)
Protected (Protected)
Private (privately)
Public (common, default) in PHP5 if the class does not have an access modifier for the specified member, the default is the access permission for the.
protected (protected) is declared as a member of the protected, allowing access only to subclasses of that class.
Private is defined as a member of private, and is visible to all members within the class, without access restrictions. Access is not allowed outside of the class.

Graphic

Demo

Copy Code code as follows:

Class woman{
Public $name = "Gaojin";
protected $age = "22";
Private $height = "170";
function info () {
Echo $this->name;
}
Private function Say () {
echo "This is the private method";
}
}
$w = new Woman ();
echo $w->info ();
echo $w->name;//Public properties can be accessed
echo $w->age;//protected Property, reporting fatal error
echo $w->height;//protected Property, reporting fatal error
Private method, access error
$w->say (); Private method, access error
Class Girl extends woman{
You can redefine the public and protected methods of the parent class, but you cannot define private
protected $name = "Jingao"; You can define a new
function info () {
Echo $this->name;
Echo $this->age;
Echo $this->height;
}
function say () {
Parent::say ()//private method cannot be inherited if the say method of the parent class is protected there is no error.
echo "I am a Girl";
}
}
$g = new Girl ();
$g->say ()/Normal output
Echo $g->height;//Private property access does not have output results
$g->info ()//This is the output Gaojin22 $height private property is not inherited
$g->height = "12";//This is redefining the Height property is also assigned
$g->info ()//So this will output gaojin2212