在函数内部设置类变量的值，并在下次调用该类时访问它

Question

我正在类中设置一个类变量。现在，我已经编写了一个使用变量的方法。我写的代码是这样的

class someController extends someBase{
private $var;
var_dump($var); //line 3
public function someFunc(){
$this->var = null
$this->var = $this->otherFunction(); //assume this returns string "Barack Obama"
}
}

第一次访问控制器时，第3行上的值将为null。如何对其进行编码，以便下次访问该控制器时，第3行的var_dump输出为"Barack Obama"。

我研究过getter和setter，但由于我是php的新手，所以我无法理解它是如何工作的。

Answer 1

<?php
class someBase{
}
class someController extends someBase{
private $var = null;
private  $count = 0;
//var_dump($var);  you can't print anything directly from class itself, you must print it inside function.
public function someFunc(){
$this->count++;
if($this->count == 1)
var_dump($this->var); // null value can't be printed by echo or print as there is no value assigned to null value. in order to print null value you should print it as string
else
echo $this->var = $this->setter_function(); 
}
private function setter_function(){
return "Barack Obama";
}
}

$obj = new someController();
$obj->someFunc();
$obj->someFunc();

?>