vladima/gist:ac211a55df453297c3f4

## gistfile1.html
<html>
<head>
    <title>Test</title>
    <script type="text/javascript">
        "use strict"
        function BigObject(x) {
            this.x = new Array(x);
        }

        var callbacks;

        function testVar() {
            callbacks = createWithVar();
        }

        function testLet() {
            callbacks = createWithLet();
        }

        function createWithVar() {
            var bigObject = new BigObject(100000);
            var result = [];
            for (var x = 0; x < 1; ++x) {
                (function(_x) {
                    var value = bigObject.x.length;
                    result.push(function() { return _x + value; });
                })(x);
            }
            return result;
        }

        function createWithLet() {
            var bigObject = new BigObject(100000);
            var result = [];
            for (let x = 0; x < 1; ++x) {
                var value = bigObject.x.length;
                result.push(function() { return x + value; });
            }
            return result;
        }

    </script>
<body>
    <button onclick="testVar()">test var</button>
    <button onclick="testLet()">test let</button>
</body>
</html>
	<html>
	<head>
	<title>Test</title>
	<script type="text/javascript">
	"use strict"
	function BigObject(x) {
	this.x = new Array(x);
	}

	var callbacks;

	function testVar() {
	callbacks = createWithVar();
	}

	function testLet() {
	callbacks = createWithLet();
	}

	function createWithVar() {
	var bigObject = new BigObject(100000);
	var result = [];
	for (var x = 0; x < 1; ++x) {
	(function(_x) {
	var value = bigObject.x.length;
	result.push(function() { return _x + value; });
	})(x);
	}
	return result;
	}

	function createWithLet() {
	var bigObject = new BigObject(100000);
	var result = [];
	for (let x = 0; x < 1; ++x) {
	var value = bigObject.x.length;
	result.push(function() { return x + value; });
	}
	return result;
	}

	</script>
	<body>
	<button onclick="testVar()">test var</button>
	<button onclick="testLet()">test let</button>
	</body>
	</html>