Nonlocal Meaning: Definition and Examples
🌐
nonlocal
[nɒnˈloʊkəl ]
Definition
programming scope
In programming, 'nonlocal' refers to a variable that is not local to the current function or block of code but is defined in an enclosing scope. This keyword allows you to modify a variable from an outer function in a nested function, providing a way to access variables from a different scope that is not the global scope.
Examples of usage
- The nonlocal keyword gives access to outer variables.
- You can use nonlocal to change the value of an enclosing scope variable.
- In Python, nonlocal helps manage variable scope in nested functions.
Interesting Facts
Science
- In physics, 'nonlocal' refers to effects or interactions that occur over a distance, not confined to adjacent areas.
- Quantum mechanics introduces nonlocality as particles can be entangled, influencing each other regardless of the distance separating them.
Philosophy
- Philosophically, the term raises questions about identity and awareness, especially in discussions of consciousness and experience outside immediate perception.
- It encourages discussions on how context can affect meaning and relevance, especially in the age of global communication.
Pop Culture
- In the realm of video games and literature, 'nonlocal' characters often represent powers or connections that extend beyond their immediate environment.
- Movies and books featuring time travel sometimes reflect nonlocal themes, where actions in one location can alter outcomes in another far-off place.
Education
- In mathematics, particularly in calculus, 'nonlocal' refers to functions or variables influenced by values from outside their immediate scope.
- Teaching strategies increasingly incorporate nonlocal references, linking local studies to global issues to enhance student understanding.
Origin of 'nonlocal'
Main points about word origin
- The prefix 'non-' comes from Latin, meaning 'not', while 'local' has roots in Latin 'localis', meaning 'pertaining to a place'.
- The term began to appear in English in the 20th century, expanding concepts of location beyond immediate surroundings.
The term 'nonlocal' originated in the context of programming languages to address issues related to variable scope. It first appeared in the Python programming language with its introduction of the 'nonlocal' keyword in version 3.0, released in December 2008. The 'nonlocal' keyword was designed to allow developers to easily modify variables that are defined in an enclosing scope, effectively bridging the gap between local and global variable access. Its usage has since been adapted in various programming practices and discussions surrounding variable scope. The term combines 'non-' meaning 'not' and 'local', which means 'pertaining to a limited area or scope'. This underscores the essence of accessing variables that exist outside of the immediate function but are still part of the active scope.