Calling a function within the function inside the class in php - php

Question

I don't understand what's going on with this. I need to call Func1 from Func2 and parametr for Func1 should be given inside the object.
class MyClass {
function Func1($a) {
return $a;
}
function Func2() {
echo $this->Func1($a);
}
}
$c = new MyClass();
$c->Func1('parametr'); // prints: 1
$c->Func2();

Answer 1

What about setting the parameter as class variable (property)?
class MyClass {
private $a;
function Func1($a) {
$this->a = $a;
return $a;
}
function Func2() {
echo $this->Func1($this->a);
}
}
This sets the parameter first time you call Func1. Then everytime you call Func2, it uses the parameter. You can also skip passing the parameter like this:
class MyClass {
private $a;
function Func1($a = null) {
if ($a === null) {
return $this->a;
} else {
$this->a = $a;
return $a;
}
}
function Func2() {
echo $this->Func1();
}
}
I.e if you call func1 without any parameter, it uses the stored variable (property), otherwise it uses the given parameter. This can be used in various ways depending on your exact needs.

Answer 2

The instruction:
echo $this->Func1($a);
is wrong: the variable $a is out of the scope of Func2. $a is a parameter of Func1 so is only int he scope of Func1.

Answer 3

You should read more about variable scopes at PHP http://php.net/manual/en/language.variables.scope.php
quick glimpse:
1) you can have global variables. to access those, use keyword global in functions that need access to that
2) you can have local variables, available only within a scope of a function
3) you can pass references to variables, so that variable from one scope is made accessible to other function/scope
4) you can have objects's internal variables of different kind (private, public, protected, static)
I suggest you get familiar with this stuff real well.
As for you code, problem is obvious. In Func2 the $a is local variable, thus when passed to $this->Func1($a), it is undefined. As your example code suggests, you might want to introduce class property private $a, and then use that. e.g.:
class X {
private $a;
function set($val){
$this->a = $val;
}
function get(){
return $this->a;
}
function doSomethingWithA(){
$this->set($this->get() * 2);
}
}