Programming Environment Concepts

Study Notes

In programming, an environment refers to the context in which a program or script is executed.
It includes the variables, functions, and objects that are available for use.
Environments can be thought of as a container that holds the state of the program.

Global Environment: The top-level environment that contains all the built-in variables, functions, and objects.
Local Environment: A temporary environment created when a function or block is executed, which contains its own local variables and objects.
Module Environment: An environment created when a module is imported, which contains the variables, functions, and objects defined in the module.

Primitive Types: Basic types that are built into the programming language, such as:
- Integers (e.g. int in Python)
- Floating-point numbers (e.g. float in Python)
- Strings (e.g. str in Python)
- Booleans (e.g. bool in Python)
Complex Types: Types that are composed of primitive types, such as:
- Lists (e.g. list in Python)
- Tuples (e.g. tuple in Python)
- Dictionaries (e.g. dict in Python)
- Objects (e.g. object in Python)
User-Defined Types: Types created by the programmer, such as:
- Classes (e.g. class in Python)
- Structures (e.g. struct in C)

Static Type System: A type system that checks the types of variables at compile-time, such as in C or Java.
Dynamic Type System: A type system that checks the types of variables at runtime, such as in Python or JavaScript.
Weak Type System: A type system that allows implicit type conversions, such as in JavaScript.
Strong Type System: A type system that does not allow implicit type conversions, such as in Python.

A program's environment includes variables, functions, and objects available for use, serving as a container for the program's state.

Global Environment: the top-level environment containing all built-in variables, functions, and objects.
Local Environment: a temporary environment created when a function or block is executed, containing local variables and objects.
Module Environment: an environment created when a module is imported, containing variables, functions, and objects defined in the module.

Basic types built into the programming language, including:
- Integers (e.g. int in Python)
- Floating-point numbers (e.g. float in Python)
- Strings (e.g. str in Python)
- Booleans (e.g. bool in Python)

Types composed of primitive types, including:
- Lists (e.g. list in Python)
- Tuples (e.g. tuple in Python)
- Dictionaries (e.g. dict in Python)
- Objects (e.g. object in Python)