What is meant by Global Variables?
Global variables are variables declared outside of all functions or blocks in a program and are visible and accessible throughout the entire program. They allow access to data in different parts of a program and have a lifetime that corresponds to the entire runtime of the program.
Typical software functions in the area of "Global Variables":
- Declaration and Initialization: Creation and value assignment of global variables outside of functions.
- Access Management: Control of access to global variables, e.g., by using keywords like "global" in Python.
- Namespace Management: Avoidance of naming conflicts between global and local variables.
- Thread Safety: Implementation of synchronization mechanisms for safe access to global variables in multi-threaded environments.
- Modular Structuring: Organization of global variables in namespaces or modules for better clarity.
- Constant Management: Management of immutable global values used throughout the program.
Examples of "Global Variables":
- Configuration Variables: Global settings that control the behavior of the entire application.
- Counters: Global variables for tracking program-wide statistics or states.
- Error Variables: Global variables like "errno" in C for storing error information.
- Database Connections: Global objects for managing database connections in an application.
- Logging Configuration: Global settings for the logging behavior of the application.
- Language Settings: Global variables for storing the current language in multilingual applications.