Structured Programming

Structured programming is a programming paradigm that restricts control flow to a small set of disciplined constructs — sequence, selection (if/then/else), and iteration (while/for) — eliminating unrestricted goto jumps. The paradigm was crystallized by Edsger Dijkstra in his seminal 1968 letter "Go To Statement Considered Harmful" and subsequently developed by Dijkstra, Tony Hoare, and Niklaus Wirth into a methodology for writing programs that are provably correct and intellectually tractable.

The core insight is not merely that goto statements are dangerous but that program understanding is a hierarchical, nested process. When control flow mirrors the logical structure of the specification, the gap between what the program should do and what it actually does becomes visible and bridgeable. Structured programming established the foundational discipline that later enabled object-oriented programming, functional programming, and modern software engineering practices.

Structured programming is frequently dismissed as an obsolete discipline from the era of punch cards, but this misses its deeper point: the structure of code should reflect the structure of thought. The fact that modern programmers routinely produce spaghetti code in supposedly structured languages proves that Dijkstra's insight was about cognitive discipline, not syntax. A language with no goto statement is not necessarily a language with no chaos.