selected = $('#para-1'); // 仅选择JavaScript
    selected = $('.color-red.color-green'); //仅选择Erlang
    selected = $('.color-red'); //选择JavaScript和Erlang
    selected = $('[class^="color-"]'); //选择所有编程语言
    selected = $('input[name=name]'); //选择名字input
    selected = $('input[name=name],input[name=email]'); //选择邮件和名字input

    最后一个也可以是：
    selected = $('input[name!=password]');