Euler 1 - Multiples of 3 and 5

by joshpauljohnson

HTML

<form>
    <section>
        Enter: <input type="number"/>
        <input type="submit" value="Go"/>
        <p>Out:</p>
        <article></article>
    </section>
</form>

JavaScript

$("form").submit(function(e) {
    e.preventDefault();
    $("article").text("Calculating...");
    $("article").text( sum3and5(parseInt($("input[type=number]").val())) );
});

var sum3and5 = function(n) {
    var ret = 0;
    for (var i = 0; i < n; i += 3) {
        ret += i;
    }
    for (var i = 0; i < n; i += 5) {
        ret += i;
    }
    return ret;
};