Tutorial by Topics: namespaces

Used to prevent name collisions when using multiple libraries, a namespace is a declarative prefix for functions, classes, types, etc. namespace identifier(opt) { declaration-seq } inline namespace identifier(opt) { declaration-seq } /* since C++11 */ inline(opt) namespace attribute-specifie...

From the PHP documentation: What are namespaces? In the broadest definition namespaces are a way of encapsulating items. This can be seen as an abstract concept in many places. For example, in any operating system directories serve to group related files, and act as a namespace for the files wi...

Element and attribute names in XML are called QNames (qualified names). A QName is made of: a namespace (a URI) a prefix (an NCName, NC because it contains no colon) a local name (an NCName) Only the namespace and the local name are relevant for comparing two QNames. The prefix is only a ...

XPath 1.0 doesn't have the concept of a default namespace. Also, the namespace prefixes defined in the original XML document do not affect XPath - namespace prefixes have to be explicitly registered with the XPath provider, otherwise prefixes can't be used at all in the XPath expression.

A code block is a piece of Python program text that can be executed as a unit, such as a module, a class definition or a function body. Some code blocks (like modules) are normally executed only once, others (like function bodies) may be executed many times. Code blocks may textually contain other c...