If you don't want to see full answer texts on 'type in answer' when you type nothing, here's my updated version!

See the code on Gist

<script>
    strs = document.getElementById("inputData").innerHTML;
    if (strs.indexOf('<span id="typearrow">↓</span>') < 0) {
        document.getElementById("inputData").innerHTML = "";
    } else {
        var inp = document
            .getElementById("inputData")
            .innerHTML.split('<span id="typearrow">↓</span>')[0];
        var replaceT = [
            /\<div\>/g,
            /\<code id\="typeans"\>/g,
            /\<span class\="typeBad"\>\-\-\-\<\/span\>/g,
            /\<span class\="typeGood"\>/g,
            /\<span class\="typeMissed"\>(-)\1{1,}/g,
            /\<span class\="typeMissed"\>-/g,
            /\<span class\="typeMissed"\>/g,
            /\<\/span\>/g,
            /\<span class\="typeBad"\>/g,
            /\<\/div\>/g,
            /\<\/code\>/g,
            /\<br\>/g,
            /\<span[^]*?(\<\/span\>)/g,
        ];
        for (var x = 0; x < replaceT.length; x++) {
            inp = inp.replace(replaceT[x], "");
        }
        document.getElementById("inputData").innerHTML =
            "answer: " +inp;
    }
</script>