diff --git a/samples/c1.php b/samples/c1.php
new file mode 100644
index 00000000..5e29ce44
--- /dev/null
+++ b/samples/c1.php
@@ -0,0 +1,14 @@
+<?php
+function add(int $a, int $b): int {
+    return $a + $b;
+}
+
+function main()
+{
+    $a = 1000;
+    $b = 999;
+    var_dump(add($a, $b));
+
+    $func = 'add';
+    var_dump($func($a, $b));
+}
diff --git a/samples/c2.php b/samples/c2.php
new file mode 100644
index 00000000..3622c623
--- /dev/null
+++ b/samples/c2.php
@@ -0,0 +1,20 @@
+<?php
+class Foo {
+    static public function func1(string $name)
+    {
+        var_dump('hello ' . $name . '!');
+    }
+
+    public function func2(string $name)
+    {
+        var_dump('hello ' . $name . '!');
+    }
+}
+
+function main()
+{
+    Foo::func1('world');
+
+    $obj = new Foo();
+    $obj->func2('php');
+}
diff --git a/samples/c3.php b/samples/c3.php
new file mode 100644
index 00000000..897b6422
--- /dev/null
+++ b/samples/c3.php
@@ -0,0 +1,6 @@
+<?php
+function main()
+{
+    require __DIR__ . '/script.php';
+    php_os();
+}
diff --git a/samples/c4.php b/samples/c4.php
new file mode 100644
index 00000000..8817f0d9
--- /dev/null
+++ b/samples/c4.php
@@ -0,0 +1,34 @@
+<?php
+class Base {
+    function bar()
+    {
+        var_dump(__METHOD__);
+    }
+
+    public function run()
+    {
+        $this->bar();
+    }
+}
+
+class Child extends Base
+{
+    function bar()
+    {
+        var_dump(__METHOD__);
+    }
+}
+
+function my_uname_func()
+{
+    var_dump(php_uname());
+}
+
+function main()
+{
+    $obj1 = new Child();
+    $obj1->run();
+
+    $obj2 = new Base();
+    $obj2->run();
+}