teramako/proto_test.html

## proto_test.html
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>__proto__ test</title>
</head>
<body>
<h1>__proto__ test</h1>

<div id="out"></div>

<script>
var $out = document.getElementById("out");
function print(msg){
  out.insertAdjacentHTML("BeforeEnd", msg);
}
// 1
var desc = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
var props = Object.getOwnPropertyNames(desc);

print(
  "<h2>Descriptor</h2>" +
  "<dl>" +
  props.map(function (key) {
    return "<dt>" + key + "</dt><dd>" + desc[key] + "</dd>"
  }).join("") +
  "</dl>"
);

var proto = {
  getName: function (){ return "PROTO"; }
};

var obj = {
  __proto__: proto
};

print("<h2>var obj = { __proto__: proto }</h2>");
print("<p>obj.__proto__ is proto: " + (Object.getPrototypeOf(obj) === proto) + "</p>");

var obj2 = Object.create(null);
print("<h2>var obj2 = Object.create(null)<h2>");
print("<p>__proto__ in obj2: " + ("__proto__" in obj2) + "</p>");
obj2.__proto__ = "OK";
print("<p>obj2 hasOwn '__proto__': " + Object.prototype.hasOwnProperty.call(obj2, "__proto__") + "</p>");

print("<p>JSON.stringify(obj2): " + JSON.stringify(obj2) + "</p>");

var obj3 = JSON.parse('{ "__proto__": "PROTO" }');
print("<h2>var obj3 = JSON.parse('{ \"__proto__\": \"PROTO\" }')</h2>");
print("<p>obj3's keys: " + Object.keys(obj3) + "</p>");
print("<p>JSON.stringify(obj3): " + JSON.stringify(obj3) + "</p>");

</script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>__proto__ test</title>
	</head>
	<body>
	<h1>__proto__ test</h1>

	<div id="out"></div>

	<script>
	var $out = document.getElementById("out");
	function print(msg){
	out.insertAdjacentHTML("BeforeEnd", msg);
	}
	// 1
	var desc = Object.getOwnPropertyDescriptor(Object.prototype, "__proto__");
	var props = Object.getOwnPropertyNames(desc);

	print(
	"<h2>Descriptor</h2>" +
	"<dl>" +
	props.map(function (key) {
	return "<dt>" + key + "</dt><dd>" + desc[key] + "</dd>"
	}).join("") +
	"</dl>"
	);

	var proto = {
	getName: function (){ return "PROTO"; }
	};

	var obj = {
	__proto__: proto
	};

	print("<h2>var obj = { __proto__: proto }</h2>");
	print("<p>obj.__proto__ is proto: " + (Object.getPrototypeOf(obj) === proto) + "</p>");

	var obj2 = Object.create(null);
	print("<h2>var obj2 = Object.create(null)<h2>");
	print("<p>__proto__ in obj2: " + ("__proto__" in obj2) + "</p>");
	obj2.__proto__ = "OK";
	print("<p>obj2 hasOwn '__proto__': " + Object.prototype.hasOwnProperty.call(obj2, "__proto__") + "</p>");

	print("<p>JSON.stringify(obj2): " + JSON.stringify(obj2) + "</p>");

	var obj3 = JSON.parse('{ "__proto__": "PROTO" }');
	print("<h2>var obj3 = JSON.parse('{ \"__proto__\": \"PROTO\" }')</h2>");
	print("<p>obj3's keys: " + Object.keys(obj3) + "</p>");
	print("<p>JSON.stringify(obj3): " + JSON.stringify(obj3) + "</p>");

	</script>
	</body>
	</html>