XPath Boolean

In XPath, boolean values are used to represent the truth or falsehood of expressions and conditions. XPath supports two boolean values: true and false. Boolean values are commonly used in predicates and expressions to filter nodes based on specific conditions.

Here are some examples of how boolean values are used in XPath:

1. Selecting Elements Based on a Condition:

//book[price < 20]

This XPath expression selects all <book> elements that have a child element named “price” with a value less than 20.

2. Combining Conditions with Logical Operators:

//book[price < 20 and @category='fiction']

This XPath expression selects all <book> elements that have both a child element named “price” with a value less than 20 and a “category” attribute with the value “fiction.”

3. Using Boolean Functions:
   XPath provides boolean functions, such as not(), contains(), starts-with(), and ends-with(), which return boolean values. These functions are often used in conjunction with other conditions to filter nodes.

For example:

//book[not(contains(title, 'Harry Potter'))]

This XPath expression selects all <book> elements that do not have a child element named “title” containing the text “Harry Potter.”

4. Testing for Existence:

//book[author]

This XPath expression selects all <book> elements that have a child element named “author.”

XPath boolean values play a crucial role in conditional expressions, allowing you to dynamically filter and select nodes in XML or HTML documents based on specific criteria. By combining boolean conditions with other XPath features, you can create powerful and flexible expressions to retrieve precisely the data you need from the document.