1. 1 Reasons for Studying Concepts of Programming Languages- CO1 x Increased ability to express ideas x Improved background for choosing appropriate languages

Definition: A subprogram (also called a subroutine) is a component of a program that carries out a specific activity or set of related activities. With the exception of co-routines and concurrent calls, subprograms exhibit the following properties:

Software II: Principles of Programming Languages Lecture 9 – Subprograms Fundamentals of Subprograms • Each subprogram has a single entry point • The calling program is suspended during execution of the called subprogram • Control always returns to the caller when the called subprogram’s execution terminates

This topic explores the key concepts and principles related to subprograms and blocks, including scope and lifetime of variables, parameter passing methods, overloaded subprograms, generic subprograms, design issues for functions, overloaded operators, co-routines, and more.

Preliminary Concepts: Reasons for studying concepts of programming languages, programming domains, language evaluation criteria, influences on language design, language categories, language design trade-offs, implementation methods, programming environments, Evolution of Major Programming Languages.

ISBN Chapter 9 Subprograms CE2004 Principles of Programming Languages. ISBN Chapter 9 Subprograms and Functions –Design Issues –Local Referencing Environments –Parameter-Passing Methods –Parameters that are Subprogram.

Unit-1(PRINCIPLES OF PROGRAMMING LANGUAGES) 1-11 Programming Methodologies Influences 1950s and early 1960s: Simple applications; worry about machine efficiency Late 1960s: People efficiency became important; readability, better control structures – structured programming – top-down design and step-wise refinement

Fundamentals of sub-programs 2. Scope and lifetime of variable 3. Static and dynamic scope 4. Design issues of subprograms and operations, local referencing environments 5. Parameter passing methods 6. Overloaded sub-programs 7. Generic sub-programs 8. Parameters that are sub-program names 9.