Seven Obscure Languages in Seven Weeks

Introducing Procedures

As a procedural language, Simula incorporates procedures and function procedures. The distinction lies in their return values. Similar to void functions in C and C++, regular procedures don’t yield a return value but instead operate through side effects, such as altering global variables and parameters or conducting input/output. On the other hand, function procedures have a specific data type and must return a value of this type. We’ll refer to both types as “procedures” for simplicity, with differentiation made only when required.

Unless declared with the EXTERNAL keyword, procedures must be defined prior to their initial usage within the same BEGIN/END block. A procedure’s definition includes the return type (for ...