Calling a function within the function inside the class in php

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 {

        f开发者_运维知识库unction Func1($a) {
              return $a;
        }
        function Func2() {
              echo $this->Func1($a);
        }
}

$c = new MyClass();

$c->Func1('parametr'); // prints: 1

$c->Func2();

---

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.

---

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.

---

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);
    }
}