How to write - If Visible selector?

Not sure how to write this;

If .sub1 is visible, .homepage fadeTo .25

Sub1 has a FadeIn and I want the homepage opacity to drop to .25 if the sub1 is open?

I have this;

 $("#cat").click(function(){
 if ($('.sub1').is(':visible') ) {
 $(".homepage").fadeTo(500, .25);}

 else {
 $(".homepage").fadeTo(500, 1);

 }

The actual website I am making > Website Mockup > Clicking Categories fade开发者_如何学运维s in the sub menu and makes homepage opacity 25%, clicking categories again, makes submenu fade Out making homepage 100%.....But clicking categories > Fashion > Mens Fashion > Smart, Brings up 'Mens Smart Fashion div" but clicking categories again fades the Mens Smart fashion div out, and brings .sub1 back, but the .homepage is 100% and not 25% when the .sub1 is open

You can filter the visible .sub1 and check the length, this may not be so great if there are multiple .sub1's, maybe add a little specificity to the selector.

This technique will filter out elements with css visibility:hidden or opacity: 0 for the first .sub1 (':eq(0)'). If the length is 0 the condition will return false.

if($('.sub1:eq(0):visible').length) {
    //.homepage fade to .25
}

Revised:

$("#cat").click(function(){
    if ($('.sub1').css('opacity') == .25 ) {  

        $('.homepage').fadeTo(500, 1);

    } else {

        $('.homepage').fadeTo(500, .25); 
    }
});

I think the reason the it would not fade back in is because your condition was checking for opacicty:0 which you never reached when fading to .25. You should set the condition to check a number .25 to avoid checking multiple strings such as '.25' or '0.25'. Firefox reports '0.25'.