Metaclasses allow you to deeply modify the behaviour of Python classes (in terms of how they're defined, instantiated, accessed, and more) by replacing the
type metaclass that new classes use by default.
In C++ Metaprogramming refers to the use of macros or templates to generate code at compile-time.
In general, macros are frowned upon in this role and templates are preferred, although they are not as generic.
Template metaprogramming often makes use of compile-time computations, whether via templates or
constexpr functions, to achieve its goals of generating code, however compile-time computations are not metaprogramming per se.
Meta tags in HTML documents provide useful information about the document including a description, keywords, author, dates of modifications and around 90 other fields. This topic covers the usage and purpose of these tags.
Metaprogramming can be described in two ways:
“Computer programs that write or manipulate other programs (or themselves) as their data, or that do part of the work at compile time that would otherwise be done at runtime”.
More simply put: Metaprogramming is writing code that writes code during runtime to make your life easier.
<meta>tags can be included in the
<head>tag of an email.
<meta>tags tell emails clients how to interpret and display email code. These are
<meta>tags that are regularly used in email.
As we all know Metadata mean data about data.
To fetch metadata of a table like total number of column, column name, column type etc. , ResultSetMetaData interface is useful because it provides methods to get metadata from the ResultSet object.