Jquery小知识

1.

$(document).ready(function(){
  $(‘form‘).find("input[type=textarea], input[type=password], textarea").each(function(ev)
  {
      if(!$(this).val()) {
     $(this).attr("placeholder", "Type your answer here");
  }
  });
});//获取属性How can I select an element by name with jQuery?

you can use the attribute selector

$(‘td[name=tcol1]‘) // matches exactly ‘tcol1‘

$(‘td[name^=tcol]‘) // matches those that begin with ‘tcol‘//通过name 选择

How can I know which radio button is selected via jQuery?

To get the value of the selected radioName item of a form called ‘myForm‘:

$(‘input[name=radioName]:checked‘, ‘#myForm‘).val()//注意这条棒哒哒的选择//判断哪个radio 被选中

使用trigger()方法模拟事件

$("#btn").trigger("click");//模拟点击http://blog.csdn.net/lijunling2008live/article/details/7457396

使用标准效果列队，举个例子，我们可以在 <div id="foo"> 的 .slideUp() 和 .fadeIn() 动画之间设置800毫秒的延时:

//设置动画延迟

setTimeout(
  function()
  {
    //do something special
  }, 5000);

//实打实的延迟5秒