常用 Xpath 选择器速查表
Selectors
Descendant selectors
CSS | Xpath | ? |
---|---|---|
h1 | //h1 | ? |
div p | //div//p | ? |
ul > li | //ul/li | ? |
ul > li > a | //ul/li/a | |
div > * | //div/* | |
:root | / | ? |
:root > body | /body |
Attribute selectors
CSS | Xpath | ? |
---|---|---|
#id | //*[@id="id"] | ? |
.class | //*[@class="class"] ...kinda | |
input[type="submit"] | //input[@type="submit"] | |
a#abc[for="xyz"] | //a[@id="abc"][@for="xyz"] | ? |
a[rel] | //a[@rel] | |
a[href^='/'] | //a[starts-with(@href, '/')] | ? |
a[href$='pdf'] | //a[ends-with(@href, '.pdf')] | |
a[href*='://'] | //a[contains(@href, '://')] | |
a[rel~='help'] | //a[contains(@rel, 'help')] ...kinda |
Order selectors
CSS | Xpath | ? |
---|---|---|
ul > li:first-of-type | //ul/li[1] | ? |
ul > li:nth-of-type(2) | //ul/li[2] | |
ul > li:last-of-type | //ul/li[last()] | |
li#id:first-of-type | //li[1][@id="id"] | ? |
a:first-child | //*[1][name()="a"] | |
a:last-child | //*[last()][name()="a"] |
Siblings
CSS | Xpath | ? |
---|---|---|
h1 ~ ul | //h1/following-sibling::ul | ? |
h1 + ul | //h1/following-sibling::ul[1] | |
h1 ~ #id | //h1/following-sibling::[@id="id"] |
jQuery
CSS | Xpath | ? |
---|---|---|
$('ul > li').parent() | //ul/li/.. | ? |
$('li').closest('section') | //li/ancestor-or-self::section | |
$('a').attr('href') | //a/@href | ? |
$('span').text() | //span/text() |
Other things
CSS | Xpath | ? |
---|---|---|
h1:not([id]) | //h1[not(@id)] | ? |
Text match | //button[text()="Submit"] | ? |
Text match (substring) | //button[contains(text(),"Go")] | |
Arithmetic | //product[@price > 2.50] | |
Has children | //ul[*] | |
Has children (specific) | //ul[li] | |
Or logic | //a[@name or @href] | ? |
Union (joins results) | //a | //div | ? |
Class check
//div[contains(concat(' ',normalize-space(@class),' '),' foobar ')]
Xpath doesn't have the "check if part of space-separated list" operator, so this is the workaround.
Expressions
Steps and axes
// | ul | / | a[@id='link'] |
---|---|---|---|
Axis | Step | Axis | Step |
Prefixes
Prefix | Example | What |
---|---|---|
// | //hr[@class='edge'] | Anywhere |
./ | ./a | Relative |
/ | /html/body/div | Root |
Begin your expression with any of these.
Axes
Axis | Example | What |
---|---|---|
/ | //ul/li/a | Child |
// | //[@id="list"]//a | Descendant |
Separate your steps with /
. Use two (//
) if you don't want to select direct children.
Steps
//div
//div[@name='box']
//[@id='link']
A step may have an element name (div
) and predicates ([...]
). Both are optional. They can also be these other things:
//a/text() #=> "Go home"
//a/@href #=> "index.html"
//a/* #=> All a's child elements
Predicates
Predicates
//div[true()]
//div[@class="head"]
//div[@class="head"][@id="top"]
Restricts a nodeset only if some condition is true. They can be chained.
Operators
# Comparison
//a[@id = "xyz"]
//a[@id != "xyz"]
//a[@price > 25]
# Logic (and/or)
//div[@id="head" and position()=2]
//div[(x and y) or not(z)]
Use comparison and logic operators to make conditionals.
Using nodes
# Use them inside functions
//ul[count(li) > 2]
//ul[count(li[@class='hide']) > 0]
# This returns `<ul>` that has a `<li>` child
//ul[li]
You can use nodes inside predicates.
Indexing
//a[1] # first <a>
//a[last()] # last <a>
//ol/li[2] # second <li>
//ol/li[position()=2] # same as above
//ol/li[position()>1] # :not(:first-of-type)
Use []
with a number, or last()
or position()
.
Chaining order
a[1][@href='/']
a[@href='/'][1]
Order is significant, these two are different.
Nesting predicates
//section[.//h1[@id='hi']]
This returns <section>
if it has an <h1>
descendant with id='hi'
.
Functions
Node functions
name() # //[starts-with(name(), 'h')]
text() # //button[text()="Submit"]
# //button/text()
lang(str)
namespace-uri()
count() # //table[count(tr)=1]
position() # //ol/li[position()=2]
Boolean functions
not(expr) # button[not(starts-with(text(),"Submit"))]
String functions
contains() # font[contains(@class,"head")]
starts-with() # font[starts-with(@class,"head")]
ends-with() # font[ends-with(@class,"head")]
concat(x,y)
substring(str, start, len)
substring-before("01/02", "/") #=> 01
substring-after("01/02", "/") #=> 02
translate()
normalize-space()
string-length()
Type conversion
string()
number()
boolean()
Axes
Using axes
//ul/li # ul > li
//ul/child::li # ul > li (same)
//ul/following-sibling::li # ul ~ li
//ul/descendant-or-self::li # ul li
//ul/ancestor-or-self::li # $('ul').closest('li')
Steps of an expression are separated by /
, usually used to pick child nodes. That's not always true: you can specify a different "axis" with ::
.
// | ul | /child:: | li |
---|---|---|---|
Axis | Step | Axis | Step |
Child axis
# both the same
//ul/li/a
//child::ul/child::li/child::a
child::
is the default axis. This makes //a/b/c
work.
# both the same
# this works because `child::li` is truthy, so the predicate succeeds
//ul[li]
//ul[child::li]
# both the same
//ul[count(li) > 2]
//ul[count(child::li) > 2]
Descendant-or-self axis
# both the same
//div//h4
//div/descendant-or-self::h4
//
is short for the descendant-or-self::
axis.
# both the same
//ul//[last()]
//ul/descendant-or-self::[last()]
Other axes
Axis | Abbrev | Notes |
---|---|---|
ancestor | ||
ancestor-or-self | ||
attribute | @ | @href is short for attribute::href |
child | div is short for child::div | |
descendant | ||
descendant-or-self | // | // is short for /descendant-or-self::node()/ |
namespace | ||
self | . | . is short for self::node() |
parent | .. | .. is short for parent::node() |
following | ||
following-sibling | ||
preceding | ||
preceding-sibling |
There are other axes you can use.
Unions
//a | //span
Use |
to join two expressions.
More examples
Examples
//* # all elements
count(//*) # count all elements
(//h1)[1]/text() # text of the first h1 heading
//li[span] # find a <li> with an <span> inside it
# ...expands to //li[child::span]
//ul/li/.. # use .. to select a parent
Find a parent
//section[h1[@id='section-name']]
Finds a <section>
that directly contains h1#section-name
//section[//h1[@id='section-name']]
Finds a <section>
that contains h1#section-name
. (Same as above, but uses descendant-or-self instead of child)
Closest
./ancestor-or-self::[@class="box"]
Works like jQuery's $().closest('.box')
.
Attributes
//item[@price > 2*@discount]
Finds <item>
and check its attributes
Testing
Browser console
$x("//div")