如何从PHP7中的数组中获取元素？

我有下一个代码，我想做的是保存并加载数组中元素的数量，并在我声明的函数中显示它们，但在我声明函数中的构造函数foreach之后，我出现了下一个错误

注意：未定义变量：$COMPLETE\u NAME

但是，如果我在函数save中声明了相同的foreach，我会得到正确的结果

<?php

class Person{

    public $name;
    public $lastName;

    public function save($name, $lastName){

        $COMPLETE_NAME = array(
            "NAME" => $name,
            "LAST_NAME" => $lastName
        );
    }

    public function show(){
        foreach($COMPLETE_NAME as $list){
            echo $list;
        }
    }

}

$person = new Person();
$person->save("nameX", "last nameX");
$person->save("nameY", "last nameY");
$person->show();
?>

---

这是一个范围问题，而且在覆盖数组时，您也会丢失第二个名称

<?php

class Person{
    // define the property as an array
    public $names = [];


    public function save($name, $lastName){
        // use $this to access the property
        // also use [] as you call this more than once

        $this->names[] = ["name" => $name,"lastname" => $lastName];
    }

    public function show(){
        // foreach over outer array
        foreach($this->names as $name){
            // echo from the inner array
            echo $name['name'] . ' ' . $name['lastname'];
        }
    }

}

$person = new Person();
$person->save("nameX", "last nameX");
$person->save("nameY", "last nameY");
$person->show();
?>

---

与所有PHP版本相同，使用：

$this->COMPLETE\u NAME

范围问题