diff --git a/src/pages/tips/object-oriented.mdx b/src/pages/tips/object-oriented.mdx
index 55b13f7..e05071e 100644
--- a/src/pages/tips/object-oriented.mdx
+++ b/src/pages/tips/object-oriented.mdx
@@ -1219,282 +1219,3 @@
 $user = $formField->toUser();
 $user->save();
 ```
-
----
-
-```c
-#include <stdio.h>
-
-typedef char* str;
-
-struct User {
-  str name;
-  int age;
-};
-
-int main() {
-  User me = {
-    .name = "Alice",
-    .age = 30
-  };
-
-  printf("name: %s\n", me.name);
-  // name: Alice
-
-  printf("age: %d\n", me.age);
-  // age: 30
-
-  return 0;
-}
-```
-
-```php
-<?php
-class User {
-  public $name;
-  public $age;
-}
-
-$user = new User();
-
-$user->name = "Alice";
-$user->age = 30;
-
-echo $user->name . PHP_EOL;
-// Alice
-
-echo $user->age . PHP_EOL;
-// 30
-```
-
-```php
-<?php
-class User {
-  public $name;
-  public $age;
-
-  public function getName() {
-    return $this->name;
-  }
-}
-
-$user = new User();
-
-$user->name = "Alice";
-$user->age = 30;
-
-echo $user->name . PHP_EOL;
-echo $user->getName() . PHP_EOL;
-// Alice
-
-echo $user->age . PHP_EOL;
-// 30
-```
-
-```php
-<?php
-class User {
-  public $name;
-  public $age;
-
-  public function setName($name) {
-
-    if (!is_string($name)) {
-      throw new Exception("name must be a string");
-    }
-
-    $this->name = $name;
-  }
-
-  public function getName() {
-    return $this->name;
-  }
-}
-
-$user = new User();
-
-$user->name = 9817298471982;  // 文字じゃねぇ
-if (!is_string($user->name)) {
-  throw new Exception("name must be a string");
-}
-
-$user->setName("Alice");
-// ok
-
-$user->setName(123);
-// Exception: name must be a string
-
-$user->age = 30;
-
-echo $user->name . PHP_EOL;
-echo $user->getName() . PHP_EOL;
-// Alice
-
-echo $user->age . PHP_EOL;
-// 30
-```
-
-```php
-<?php
-class User {
-  // private $name;
-  protected $name;
-
-  public $age;
-
-  public function setName($name) {
-
-    if (!is_string($name)) {
-      throw new Exception("name must be a string");
-    }
-
-    $this->name = $name;
-  }
-
-  public function getName() {
-    return $this->name;
-  }
-}
-
-$user = new User();
-
-$user->name = 9817298471982;
-if (!is_string($user->name)) {
-  throw new Exception("name must be a string");
-}
-
-$user->setName("Alice");
-// ok
-
-$user->setName(123);
-// Exception: name must be a string
-
-$user->age = 30;
-
-echo $user->name . PHP_EOL;
-echo $user->getName() . PHP_EOL;
-// Alice
-
-echo $user->age . PHP_EOL;
-// 30
-```
-
-constructor コンストラクタ
-static
-
-```php
-<?php
-class User {
-
-  protected $id;
-  protected $name;
-  protected $age;
-
-  public function __construct($name) {
-    echo "newされました";
-
-    $this->name = $name;
-    $this->age = 0;
-  }
-
-  public static function findUser($id) {
-
-    // $name を使ってDBから取ってくる
-
-    $data = [
-      "name" => "bob",
-      "age" => 35,
-    ];
-
-    $instance = new User($data["name"]);
-    $instance->age = $data["age"];
-
-    return $instance;
-  }
-
-  public function setName($name) {
-
-    if (!is_string($name)) {
-      throw new Exception("name must be a string");
-    }
-
-    $this->name = $name;
-  }
-
-  public function getName() {
-    return $this->name;
-  }
-}
-
-$user = new User("Alice");
-
-$bob = User::findUser(1);
-
-$user->name = 9817298471982;
-if (!is_string($user->name)) {
-  throw new Exception("name must be a string");
-}
-
-$user->setName("Alice");
-// ok
-
-$user->setName(123);
-// Exception: name must be a string
-
-$user->age = 30;
-
-echo $user->name . PHP_EOL;
-echo $user->getName() . PHP_EOL;
-// Alice
-
-echo $user->age . PHP_EOL;
-// 30
-```
-
-```php
-<?php
-
-class User {
-  protected $id;
-  protected $user;
-  protected $age;
-
-  public function __construct($name) {
-    echo "私は {$name} です";
-    $this->name = $name;
-  }
-
-  public function setName($name) {
-
-    if (!is_string($name)) {
-      throw new Exception("name must be a string");
-    }
-
-    $this->name = $name;
-  }
-
-  public function getName() {
-    return $this->name;
-  }
-}
-
-$user1 = new User("Alice");
-// 私は Alice です
-
-
-
-class ParttimeUser extends User {
-  public function __construct($name) {
-    echo "吾輩は {$name} です";
-    $this->name = $name;
-  }
-}
-
-$user2 = new ParttimeUser("Bob");
-// 吾輩は Bob です
-
-$user2->setName("George");
-```
-
-スマホでボリュームを上げ下げしたいとき、ボタンを押させる。
-中身に触れさせて、この端子をさわってね みたいなことはさせない。