Selector type　　   CSS　　　　　　   jQuery　　　        　     What it doesTag name　　　　   p{}　　　　　    　$('p')　　　　       selects all 'p' in the documentID　　　    #some-id {}　　   $('#some-id')　　       selects the single element in the document that has as ID of some-idClass　    .some-class {}　 $('.some-class')　       selects all elements in the document that have a class of some-class

$('#some-ID')$('.some-Class')$('selected-plays > li').addClass('horizontal')$('#selected-plays li:not(.horizontal)').addClass('sub-level')

$('img[alt]') $('a[href^="mailto"]').addClass('mailto')$('a[href$=".pdf"]').addClass('pdflink')$('a[href^="http"] [href*="henry"]')

$('div.horizontal:eq(1)') //这个是JS选择器，所以select the second item from a set of <div> elements with class of horizontal //JS selector is zero-based, CSS selector is one-based
$('div:nth-child(1)')//这个是css选择器，所以Select all div selectors that are the first child of their parent$('div:first-child')//可以用JS选择器代替

$('td:contains(Henry)').addClass('highlight');
//contains() selector 是case sensitive

$('tr:even').addClass('alt');

$('input[type="radio"] ： checked')
//select all checked radio buttons but not checkboxes
$('input[type="password"], input[type="text"] : disabled')
//select all password input and disabled text input

$('tr').filter(':even').addClass('alt');$('a').filter(function(){return this.hostname && this.hostname != location.hostname;
}).addClass('external');
//filter the a tag
//must have href attribute with a domain name(this.hostname)
//the domain name that they link to must not match the domian name of the current page(location.hostname)

$('td:contains(Henry)').next().next().addClass('highlight');//后面的后面

$('td:contains(Henry)').nextAll().addClass('highlight');　　//全部Herny后面的cell

$('td:contains(Henry)').next().addClass('highlight');//only very next sibling

$('td:contains(Henry)').nextAll().andSelf().addClass('highlight');
//select all nextAll of Herny tag and itself
//mean all the row

$('td:contain(Henry)').parent().children().addClass('highlight');
//select every cell in each row where at least one of the cells contains Henry