50.5 Functional programming

50.5.1 Helper function

A helper function is a small, specialized function designed to support a larger function by handling a specific subtask. Unlike normal functions, which are often used independently as part of a program’s main functionality, helper functions are typically internal and not meant for direct external use. They improve code readability, reduce redundancy, and simplify complex logic by breaking it into smaller, manageable pieces. Normal functions are often part of a module’s public API, designed to be reused across different parts of a program. In contrast, helper functions are usually private, assisting only specific functions or modules. While normal functions perform the main operations of a program, helper functions serve a supporting role, enhancing modularity and maintainability.

Comparison Table:

	Normal Function	Helper Function
Purpose	Performs a primary operation	Supports another function
Scope	Can be used anywhere in the program	Usually private, used within a specific function/module
Reusability	Often reusable in multiple contexts	Typically used in a specific function/module
Standalone?	Yes, works independently	No, assists another function
Example	A function that calculates total price	A function that formats the price for display