C++ Coding Standards: 101 Rules, Guidelines, and Best Practices

20. Avoid long functions. Avoid deep nesting

Summary

Short is better than long, flat is better than deep: Excessively long functions and nested code blocks are often caused by failing to give one function one cohesive responsibility (see Item 5), and both are usually solved by better refactoring.

Discussion

Every function should be a coherent unit of work bearing a suggestive name (see Item 5 and the Discussion in Item 70). When a function instead tries to merge such small conceptual elements inside a long function body, it ends up doing too much.

Excessive straight-line function length and excessive block nesting depth (e.g., if, for, while, and try blocks) are twin culprits that make functions more difficult to understand and maintain, and ...