XPath Interview Questions

XPath stands for XML Path Language. It is defined as a query language for selecting nodes from an XML document. It is used to find values such as strings, numbers, or Boolean values from the content of an XML document. It is generally used to navigate through elements and attributes in an XML document. It adopts path like syntax to identify and navigate nodes in an XML document. It uses syntax for defining parts of an XML document It contains a library of standard functions. It follows the W3C(World Wide Web Consortium) recommendation.

XPath Path Expressions are a combination of variables and operators. To select nodes or node-sets in an XML document XPath uses path expressions that are used in JavaScript, Java, XML Schema, PHP, Python, C and C++, and lots of other languages. It looks like the expressions with a traditional computer file system.

XPath stands for is used to find the location of any element on a webpage or to navigate through elements and attributes in an XML document.

There are seven types of nodes specified in the Xpath that can be the output of the execution of the XPath expression. These are as follows:

• Root
• Element
• Text
• Attribute
• Comment
• Processing Instruction
• Namespace

An XPath Axes defines the node-set relative to the current (context) node. It is used to locate the node that is relative to the node on that tree.

Different XPath Axes are listed below:

An atomic value is a value in or an instance in the value space of an atomic type defined by XML Schema. Atomic values are consists of strings, integers, decimals, dates, etc. and these values are known as atomic because they cannot be subdivided.

Xpath Node is defined as a point where the path address initiates, as it follows a concept of nodes. Basically, it is an individual element of the Xpath hierarchical structure which is termed as a node and enables an XSL processing.

The features of XPath are :

• XPath defines structure
• XPath provides path expression
• XPath is a core component of
• XSLT XPath is a standard function.

In Xpath, an attribute can be used to compare using operators.

XPath uses operators on nodes such that it returns either a node-set, a string, a Boolean, or a number. Some of the examples are addition, subtraction, Multiplication, etc.

Using XPath-Multiple, we can write the Java code along with the dynamic XPath location as: findElement(By. xpath("//*[@id=' lst-ib'][@class=' gsfi lst-d-f']"));

You can compare two values in Xpath with the help of the following steps:

• Create the path to the first node set that you want to compare.
• Then, type = (equal to), != (not equal to), > (greater than), >= (greater than or equal to), < (less than), or <= (less than or equal to), depending on how you want to compare the two values.
• Finally, type a value or a path to the node-set that you want to compare with the first node set identified in Step 1.

Predicate refers to the XPath expression written in square brackets. It restricts the selected nodes in a node-set for some conditions.

The preceding-sibling axis indicates all the nodes that have the same parent as the context node such that they appear before the context node in the source document.

The normalize-space function strips white-space from a string to replace sequences of whitespace characters with a single space and return the resulting string.