Question

I’m using the following HTML and JavaScript to display the value of the #username <input> element:

<form action="#" method="post">
  Username: <input type="text" name="username" /><br />
  Password: <input type="password" name="password" /><br />
  <input class="test" type="submit" id="thing" value="Log In" />
</form>

$(document).ready(function() {
  $('input#thing').on('click', function() {
    var name = $('#username').val;
    alert(name);
  });
});​

When I run it in my browser, I get an alert saying

function (value) {
    var hooks, ret, isFunction, elem = this[0];
    if (!arguments.length) {
        if (elem) {
            hooks = jQuery.valHooks[elem.type] ||
                jQuery.valHooks[elem.nodeName.toLowerCase()];
            if (hooks &&
                "get" in hooks &&
                (ret = hooks.get(elem, "value")) !== undefined) {
                return ret;
            }
            ret = elem.value;
            return typeof ret === "string" ? ret.replace(rreturn, "") : ret == null ? "" : ret;
        }
        return;
    }
    isFunction = jQuery.isFunction(value);
    return this.each(function (i) {var val, self = jQuery(this);if (this.nodeType !== 1) {return;}if (isFunction) {val = value.call(this, i, self.val());} else {val = value;}if (val == null) {val = "";} else if (typeof val === "number") {val += "";} else if (jQuery.isArray(val)) {val = jQuery.map(val, function (value) {return value == null ? "" : value + "";});}hooks = jQuery.valHooks[this.type] || jQuery.valHooks[this.nodeName.toLowerCase()];if (!hooks || !("set" in hooks) || hooks.set(this, val, "value") === undefined) {this.value = val;}});
}

When it should be saying what the typed username is.

What’s happening?

Answer 1

The following code assigns the function val to the variable name.

    var name = $('#username').val;
    alert(name);

You’re then passing the function into alert. If you want to pass the value in the text box, you have to invoke the function and pass its return value:

    var name = $('#username').val();
    alert(name);