JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD MCA 2018 WEB TECHNOLOGIES Previous Question Paper (January - 2018 - R13)

In PHP, a constant variable is defined using the define() function. Unlike standard variables, constants do not require a dollar sign ($) prefix, are global in scope, and their values cannot be changed or undefined once set. By convention, constant names are written in uppercase letters.

The syntax is define(name, value, case_insensitive), where the third parameter is an optional boolean that defaults to false.

Example:

XML element and attribute names must adhere to specific naming conventions to ensure they are well-formed and parsable. The fundamental rules are as follows:

• Names must start with a letter or an underscore (_). They cannot start with a number or a punctuation character.
• After the first character, names can contain letters, digits, hyphens (-), underscores (_), and periods (.).
• Names cannot contain spaces.
• Names cannot start with the string 'xml', 'XML', 'Xml', or any other case variation, as these are reserved for XML standardization purposes.
• Names are case-sensitive; for example, <Name> and <name> are treated as distinct elements.
• While names can contain colons (:), they should be avoided unless used specifically for namespaces, as the colon is reserved for that purpose.