XPath query to select all href attributes of tag, which 'class' attribute equals specified string

Question

I don\'t know why following query doesn\'t work:

//a/@href[@class=\'specified_string\']

Answer 1

An attribute cannot have attributes. Only elements can have attributes.

The original XPath expression:

//a/@href[@class='specified_string'] 

selects any href attribute of any a element, such that the href attribute has an attribute class whose value is 'specified_string'.

What you want is:

//a[@class='specified_string']/@href 

that is: the href attribute of any a element that has class atribute with value 'specified_string'.