[xpath] How can I match on an attribute that contains a certain string?

I am having a problem selecting nodes by attribute when the attributes contains more than one word. For example:

<div class="atag btag" />

This is my xpath expression:

//*[@class='atag']

The expression works with

<div class="atag" />

but not for the previous example. How can I select the <div>?

I came here searching solution for Ranorex Studio 9.0.1. There is no contains() there yet. Instead we can use regex like:

div[@class~'atag']

To add onto bobince's answer... If whatever tool/library you using uses Xpath 2.0, you can also do this:

//*[count(index-of(tokenize(@class, '\s+' ), $classname)) = 1]

count() is apparently needed because index-of() returns a sequence of each index it has a match at in the string.

EDIT: see bobince's solution which uses contains rather than start-with, along with a trick to ensure the comparison is done at the level of a complete token (lest the 'atag' pattern be found as part of another 'tag').

"atag btag" is an odd value for the class attribute, but never the less, try:

//*[starts-with(@class,"atag")]

A 2.0 XPath that works:

//*[tokenize(@class,'\s+')='atag']

or with a variable:

//*[tokenize(@class,'\s+')=$classname]

For the links which contains common url have to console in a variable. Then attempt it sequentially.

webelements allLinks=driver.findelements(By.xpath("//a[contains(@href,'http://122.11.38.214/dl/appdl/application/apk')]"));
int linkCount=allLinks.length();
for(int i=0; <linkCount;i++)
{
    driver.findelement(allLinks[i]).click();
}

Be aware that bobince's answer might be overly complicated if you can assume that the class name you are interested in is not a substring of another possible class name. If this is true, you can simply use substring matching via the contains function. The following will match any element whose class contains the substring 'atag':

//*[contains(@class,'atag')]

If the assumption above does not hold, a substring match will match elements you don't intend. In this case, you have to find the word boundaries. By using the space delimiters to find the class name boundaries, bobince's second answer finds the exact matches:

//*[contains(concat(' ', normalize-space(@class), ' '), ' atag ')]

This will match atag and not matag.

You can try the following

By.CssSelector("div.atag.btag")

mjv's answer is a good start but will fail if atag is not the first classname listed.

The usual approach is the rather unwieldy:

//*[contains(concat(' ', @class, ' '), ' atag ')]

this works as long as classes are separated by spaces only, and not other forms of whitespace. This is almost always the case. If it might not be, you have to make it more unwieldy still:

//*[contains(concat(' ', normalize-space(@class), ' '), ' atag ')]

(Selecting by classname-like space-separated strings is such a common case it's surprising there isn't a specific XPath function for it, like CSS3's '[class~="atag"]'.)

try this: //*[contains(@class, 'atag')]

Here's an example that finds div elements whose className contains atag:

//div[contains(@class, 'atag')]

Here's an example that finds div elements whose className contains atag and btag:

//div[contains(@class, 'atag') and contains(@class ,'btag')]

However, it will also find partial matches like class="catag bobtag".

If you don't want partial matches, see bobince's answer below.