XPath is a query language commonly used for navigating and selecting elements in XML documents.
Within XPath, the expressions ‘.//’ and ‘//*’ serve different purposes.
The expression ‘.//’ is a condensed form of ‘descendant-or-self::node()’, which selects all elements in the document, starting from the current node. It is frequently employed to search for elements within a specific context.
Conversely, the expression ‘//*’ selects all elements in the document, regardless of their position. This more general selector allows for locating elements anywhere in the XML structure.
The primary distinction between these two expressions lies in their respective starting points. ‘.//’ initiates the search from the current node, whereas ‘//*’ commences from the root of the document. This distinction holds significance when utilizing XPath in various scenarios.
It is important to note that the reliability of information from w3schools.com, a website offering explanations on XPath syntax and axes, may vary.
What is it?
The difference between .// and // in XPath is that .// selects elements at or beneath the current node, while // selects all elements in the document.
This difference is based on the use of the dot (.) and the asterisk (*) in the XPath expressions.
The dot represents the current processing node, and when used with //. it means that the search for elements starts at the current node and includes all child elements.
On the other hand, the double forward slash (//) without the dot selects all elements in the document without considering the current node.
This distinction is important when specifying the scope of the search in XPath expressions.
Usage and Syntax
One can distinguish the usage and syntax of .// and //* in XPath.
The .// expression is used to select elements in the current node and all its descendants. It starts searching from the current node and goes down the hierarchy, matching any elements that meet the specified conditions.
On the other hand, the //* expression is used to select all elements in the document, regardless of their position. It starts searching from the root of the document and matches any elements that meet the specified conditions.
The main difference between .// and // lies in the starting point of the search. While .// starts from the current node, // starts from the root of the document.
Selecting Elements
When selecting elements in XPath, there are two types: named elements and any elements.
Named elements refer to the root element and are specified by using the element’s name, such as ‘//elementName’. This will select all elements in the document with the specified name.
On the other hand, any elements refer to all child elements of the context node and are represented by using ‘‘, such as ‘// ‘. This will select all elements in the document, regardless of their name.
The use of ‘‘ is particularly useful when you want to select elements based on a specific attribute or condition, but you are unsure of the element’s name. By using ‘‘, you can match any element that meets the specified criteria.