Obviously I rubbed some people the wrong way, and didn’t explain my question(s) clearly enough from the outset, then got wrapped up in taking some offense from some of the responses. Reviewing everything today I can see where I could have responded differently, and more clearly, earlier on. Apologies to anyone who was offended (if anyone was).
I do think the original point(s) were somewhat lost. To the original poster who offered the banking analogy – thank you. However, I don’t think it’s enough, and is clearly at odds with some of my other experiences with Java/Groovy. Let me show two code samples here (assuming WP doesn’t mangle the code too much – I need to get one of those code display plugins in here!)
In Groovy (Java), if I run this:
===========================
class person {
private email = “person email”
protected phone = “person phone”
public name = “person name”
def showInfo() {
println this.email + ” ” + this.name + ” ” + this.phone
this.onlyInUser()
}
}
class user extends person {
private email = “user email”
protected phone = “user phone”
public name = “user name”
def onlyInUser() {
println “I’m in the user class definition”
}
def showInfo() {
super.showInfo()
println this.email + ” ” + this.name + ” ” + this.phone
}
}
def u = new user()
u.showInfo()
===========================
I get this output:
===========================
person email person name person phone
I’m in the user class definition
user email user name user phone
===========================
*All* the *this* property accesses are class-bound, it seems, but the this.onlyInUser() call still calls the method in the child class.
In C# (my C# isn’t hot, but this *seems* to be a correct re-implementation of the same logic) if I run :
===========================
using System;
class person {
public string name = “person name”;
protected string email= “person email”;
private string phone = “person phone”;
public virtual void showInfo() {
Console.WriteLine(“In the person showInfo method”);
Console.WriteLine( this.name + ” ” + this.phone + ” ” + this.email);
}
}
class User : person {
public new string name = “user name”;
protected new string email= “user email”;
private new string phone = “user phone”;
public override void showInfo() {
base.showInfo();
Console.WriteLine(“In the user showInfo method”);
Console.WriteLine( this.name + ” ” + this.phone + ” ” + this.email);
}
// Main begins program execution.
public static void Main()
{
User u = new User();
u.showInfo();
}
}
===========================
I get
===========================
In the person showInfo method
person name person phone person email
In the user showInfo method
user name user phone user email
===========================
Running seemingly equivalent code in PHP (5.2.5)
===========================
<?php
error_reporting(E_ALL);
class person {
private $email = “private person email”;
protected $phone = “protected person phone”;
public $name = “public person name”;
public function showInfo() {
echo $this->email.” – “.$this->phone.” – “.$this->name.”\n”;
$this->onlyInUser();
}
}
class user extends person {
private $email = “private user email”;
protected $phone = “protected user phone”;
public $name = “public user name”;
public function onlyInUser() {
echo “I’m in the user class definition\n”;
}
public function showInfo() {
parent::showInfo();
echo $this->email.” – “.$this->phone.” – “.$this->name.”\n”;
}
}
$u = new user();
$u->showInfo();
===========================
I get the following output:
===========================
private person email – protected user phone – public user name
I’m in the user class definition
private user email – protected user phone – public user name
===========================
There’s clearly a difference here, and it’s likely related to an logical difference between super and parent. My limited Java-fu and C#-fu being what they are, I’m not able to quite grok why there’s a difference in behaviour between the examples ago.
Hopefully this is humble enough to garner some collective wisdom. I’m not bashing PHP here, nor anyone’s contributions or anything of the sort. Simply asking – why are these behaving differently?
