Newbie stuck on a jQuery question...conditional statement

So I'm a complete newbie and stuck on a conditional statement. Here's my code:

<script type="text/javascript">
$(document).ready(function(){
 if($('span.fc_cart_item_price_total') == 0) {
  $(span.fc_info).addClass('foo');
 };
});
</script>

So I'm attempting to see if span with a class of "fc_cart_item_price_total" has a value of "0", to then add a class of "foo" to the span with a class of ".fc_info". This code above is not working. Here's the HTML:

<span class="fc_info">Info 1</span><br />
<span class="fc_cart_item_price_total">$0.00</span><br />开发者_JAVA百科
<span class="fc_info">Info 2</span>

Here's the other challenge I have. I'm trying to select the span with the value of "fc_info" before the span with the class of "fc_cart_item_price_total" but have no idea of how to just select this one span.

Comparing with 0 is not the best that you can do. Try this instead:

if (!parseFloat($('.fc_cart_item_price_total').text()) {
....

Use ParseInt or ParseFloat depending on the data you expect.

For each cart item whose price is $0.00, this will add the "foo" class to the preceding (and only the preceding) fc_info.

$(function() {
    $(".fc_cart_item_price_total:contains($0.00)").each(function(i, n) {
        (n=$(n)).prevAll(".fc_info:first").addClass("foo");
    });
});

I think you need to get the HTML out of the span. Something like:

<script type="text/javascript">
$(document).ready(function(){
 if($('span.fc_cart_item_price_total').text() == 0) {
  $(span.fc_info).addClass('foo');
 };
});
</script>

But then you need to compare it to "$0.00" or trim the $ off before comparing.

the below should work...please try

<script type="text/javascript">
    $(document).ready(function(){
     if($('.fc_cart_item_price_total').text() == 0) {
      $('.fc_info').addClass('foo');
     };
    });
    </script>

To make the above code working

<script type="text/javascript">
$(document).ready(function(){
 if($('span.fc_cart_item_price_total').html() == 0) {
  $(span.fc_info:first).addClass('foo');
 };
});
</script>

And to select the first class fc_info

Use $(".fc_info:first") as your selector