Importing variables into a class - php

Question

I would like to ask, if there is a way, to use variables in a class, that were declared out of it.
Example:
$foo = 'bar';
class foobar{
function example(){
echo "foo{$foo}";
}
}
$foobar = new foobar;
$foobar->example();
This code produces a notice: Notice: Undefined variable: foo
Is there a way to make it work? Or is there some work-around?

Answer 1

You could give this argument to your class with a constructor
class foobar{
private $foo;
public function __construct($name) {
$this->foo = $name;
}
}
and then use it.
Or what PeeHaa means, you could change your method to
function example($param){
echo "foo{$param}";
}
and call it like this
$foobar->example($foo);

Answer 2

Use a construct to import it or use the global keyword. You could do something like this:
$var = 'value';
class foobar {
private $classVar;
function __construct($param) {
$this->classVar = $param;
}
}
And initiate it like this:
$var = 'value';
$inst = new foobar($var);
Or you can use global variables (which I wouldn't recommend in this case) and do something like this:
$var = 'value';
class foobar {
global $var;
function show() {
echo $var;
}
}
UPDATE: To use a class within another class, it may be instantiated in the constructor if its instance is needed throughout implementation, or it may be instantiated only when needed.
To create a reference to another class inside the constructor, do something like this:
class class1 {
private $someVar;
function __construct() {
$this->someVar = 'success';
}
function doStuff() {
return $this->someVar;
}
}
class class2 {
private $ref;
private $val;
function __construct() {
$this->ref = new class1();
$this->val = $this->ref->doStuff();
// $this->val now holds the value 'success'
}
}
$inst = new class2(); // upon calling this, the $val variable holds the value 'success'
Or you can call it only when needed, like so:
class class1 {
private $someVar;
function __construct() {
$this->someVar = 'success';
}
function doStuff() {
return $this->someVar;
}
}
class class2 {
private $ref;
private $val;
function __construct() {
// do something
}
function assign() {
$this->ref = new class1();
$this->val = $this->ref->doStuff();
// $this->val now holds the value 'success'
}
}
$inst = new class2(); // the $val variable holds no value yet
$inst->assign(); // now $val holds 'success';
Hope that helps you.

Answer 3

Yes add
class foobar{
function example(){
global $foo;
echo "foo{$foo}";
}
}
** putting it in another class is better though, or passing it to the method you're using is better too **