ivanpepelko/hamming.js

## hamming.js
<!DOCTYPE html>
<html>
    <head>
        <title>Hamming</title>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
    </head>
    <body>
        <form>
            <label for="binary">Number:</label>
            <input type="text" name="binary" id="binary"/>
            <input type="submit" value="Correct" />
        </form>
        <ul>
            <li>Error at bit: <span id="errorBit"></span></li>
            <li>Corrected sequence: <span id="correctSequence"></span></li>
        </ul>
        <script type="text/javascript">
            document.querySelector('form').addEventListener('submit', function (e) {
                e.preventDefault();
                var seq = (new FormData(e.target)).get('binary').trim();

                if (seq.match(/[01]{7}/)) {
                    var errorBit = parseInt(
                            String((seq[0] + seq[1] + seq[2] + seq[3]).replace(/0/g, "").length % 2) +
                            String((seq[0] + seq[1] + seq[4] + seq[5]).replace(/0/g, "").length % 2) +
                            String((seq[0] + seq[2] + seq[4] + seq[6]).replace(/0/g, "").length % 2), 2);

                    var correctSequence = seq;
                    if (errorBit > 0) {
                        var ei = errorBit - 1; // ei = error bit index
                        var bits = seq.split('').reverse();
                        bits[ei] = bits[ei] === "0" ? "1" : "0";
                        correctSequence = bits.reverse().join('');
                    }

                    document.getElementById("errorBit").textContent = errorBit;
                    document.getElementById("correctSequence").textContent = correctSequence;
                }
            });
        </script>
    </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>Hamming</title>
	<meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	</head>
	<body>
	<form>
	<label for="binary">Number:</label>
	<input type="text" name="binary" id="binary"/>
	<input type="submit" value="Correct" />
	</form>
	<ul>
	<li>Error at bit: <span id="errorBit"></span></li>
	<li>Corrected sequence: <span id="correctSequence"></span></li>
	</ul>
	<script type="text/javascript">
	document.querySelector('form').addEventListener('submit', function (e) {
	e.preventDefault();
	var seq = (new FormData(e.target)).get('binary').trim();

	if (seq.match(/[01]{7}/)) {
	var errorBit = parseInt(
	String((seq[0] + seq[1] + seq[2] + seq[3]).replace(/0/g, "").length % 2) +
	String((seq[0] + seq[1] + seq[4] + seq[5]).replace(/0/g, "").length % 2) +
	String((seq[0] + seq[2] + seq[4] + seq[6]).replace(/0/g, "").length % 2), 2);

	var correctSequence = seq;
	if (errorBit > 0) {
	var ei = errorBit - 1; // ei = error bit index
	var bits = seq.split('').reverse();
	bits[ei] = bits[ei] === "0" ? "1" : "0";
	correctSequence = bits.reverse().join('');
	}

	document.getElementById("errorBit").textContent = errorBit;
	document.getElementById("correctSequence").textContent = correctSequence;
	}
	});
	</script>
	</body>
	</html>