Question

I know else if works on jQuery so where’s the problem in this code:

if (document.location.href.indexOf('#1')) {
    $(".products li").fadeIn();
}
else if (document.location.href === '#2') {
    $(".products li").fadeOut();
    $(".products li.2").stop(true,true).fadeIn(200);
}
else if (document.location.href === '#3') {
    $(".products li").fadeOut();
    $(".products li.3").stop(true,true).fadeIn(200);
}
else if (document.location.href === '#4') {
    $(".products li").fadeOut();
    $(".products li.4").stop(true,true).fadeIn(200);
}
else if (document.location.href === '#5') {
    $(".products li").fadeOut();
    $(".products li.5").stop(true,true).fadeIn(200);
}
else if (document.location.href === '#6') {
    $(".products li").fadeOut();
    $(".products li.6").stop(true,true).fadeIn(200);
}
else {
    $(".products li").fadeIn();
}

If i put only if instead of else if it works but it’s not correct.

Answer 1

The expression document.location.href.indexOf('#1') will return -1 if no match is found, and zero if it matches at the start of the string. Since you test for falsey values, you’ll never have a false result (-1 evaluates as a Boolean true). You should have written:

if (document.location.href.indexOf('#1')>-1) {

But since you appear to be comparing hashes, let’s just do those directly instead (and use the proper window.location while we’re at it):

if (window.location.hash == '#1') {
    // ...
} else if (window.location.hash == '#2') {
    // etc.

That said, in your case, we can do this entirely without the if/else just by parsing that hash string:

var hash = window.location.hash.substr(1); // remove leading #
if (hash) {
    $(".products li").fadeOut();
    $(".products li."+hash).stop(true,true).fadeIn(200);
} else {
    $(".products li").fadeIn();
}