匹配其父元素下的第N个子或奇偶元素
':eq(index)' 只匹配一个元素，而这个将为每一个父元素匹配子元素。:nth-child从1开始的，而:eq()是从0算起的！
可以使用:
Matches the nth-child of its parent.
While ':eq(index)' matches only a single element, this matches more then one: One for each parent. The specified index is one-indexed, in contrast to :eq() which starst at zero.
[
Karl ,
Tane ]
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:first-child
匹配第一个子元素
':first' 只匹配一个元素，而此选择符将为每个父元素匹配一个子元素
Matches the first child of its parent.
While ':first' matches only a single element, this matches more then one: One for each parent.
返回值
Array
示例
在每个 ul 中查找第一个 li
HTML 代码:
jQuery 代码:
$("ul li:first-child")
结果:
[
John , Glen ]
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:last-child
匹配最后一个子元素
':last'只匹配一个元素，而此选择符将为每个父元素匹配一个子元素
Matches the last child of its parent.
While ':last' matches only a single element, this matches more then one: One for each parent.
返回值
Array
示例
在每个 ul 中查找最后一个 li
HTML 代码:
jQuery 代码:
$("ul li:last-child")
结果:
[
Brandon , Ralph ]
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:only-child
如果某个元素是父元素中唯一的子元素，那将会被匹配
如果父元素中含有其他元素，那将不会被匹配。
Matches the only child of its parent.
If the parent has other child elements, nothing is matched.
返回值
Array
示例
在 ul 中查找是唯一子元素的 li
HTML 代码:
jQuery 代码:
$("ul li:only-child")
结果:
[
Glen ]
--------------------------------------------------------------------------------
:input
匹配所有 input, textarea, select 和 button 元素
Matches all input, textarea, select and button elements.
返回值
Array
示例
查找所有的input元素
HTML 代码:
jQuery 代码:
$(":input")
结果:
[
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:text
匹配所有的单行文本框
Matches all input elements of type text.
返回值
Array
示例
查找所有文本框
HTML 代码:
jQuery 代码:
$(":text")
结果:
[
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:password
匹配所有密码框
Matches all input elements of type password.
返回值
Array
示例
查找所有密码框
HTML 代码:
jQuery code:
$(":password")
Result:
[
-------------------------- -------------------------------------------------- --
:radio
Match all radio buttons
Matches all input elements of type radio.
Return value
Array
Example
Find all radio buttons
HTML code:
jQuery code:
$(":radio")
Result:
[
-------------------------- -------------------------------------------------- --
:submit
Match all submit buttons
Matches all input elements of type submit.
Return value
Array
Example
Find all submit buttons
HTML code:
jQuery code:
$(":submit")
Result:
[
The others are the same: image ,:reset,:button,:file,:hidden !@# @!%$%
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