Functions & Tenary operaions

Nothing to describe here, just take a look at examples and you'll love this technique.

Target: hide sidebar when window width is less than 800px.

#1 - Lame

$(window).on('resize', function() {
    if($(this).width() > 800) {
        $('#sidebar').show();
    } else {
        $('#sidebar').hide();
    }
}).trigger('resize');

#2 - Ain't bad

$(window).on('resize', function() {
    $(this).width() > 800 ? $('#sidebar').show() : $('#sidebar').hide();
}).trigger('resize');

#3 - Like a boss

$(window).on('resize', function() {
    $('#sidebar')[$(this).width() > 800 ? 'show' : 'hide']();
}).trigger('resize');

As you see, the 3rd technice is the cleanest one and 100% valid. Now go and start coding like a boss.