CSC 1060 Week 11 More Functions

Course Objectives

• Pass arguments by reference and understand the difference between pass-by-value and pass-by-reference.
• Use function overloading and/or default parameters.
• Create and build multi-file projects.
• Demonstrate understanding and use of recursion in a program.
• Design and implement functions using a three-tier architecture model.

Agenda Week 11

• Multi-file projects
• Macro Guard
• Pass by Value / Pass by Reference
• Function Overloads
• Function Default Arguments
• Recursive Functions
• Three-Tier Architecture Model
• TODO
• Resources for help

Review

• Pick 3 questions from 5.15 Mixed-Code Exercises.
• Toggle questions to Parsons Mixed Up Code if Active Write Code is showing.

Header Files

• Header files are #included and NOT compiled.
• Source files are compiled and NOT #included.
• System header files are built into C++. Examples: <iostream>, <string>.
• Programmer-defined header files have a .h extension. Example: "programmerHeader.h"

Header Files and Source Files

• Header files are #included, while source files are compiled.
• Never #include "fileName.cpp".
• Header files have declarations (function prototypes).
• Source files contain implementation (definitions).

Build (Make) a Multi-File Program

• Pre-processor replaces #include with header file content.
• Compiler compiles each source file (.cpp) and checks syntax, creating object files (.obj).
• Linker links object files together to create the executable file (.exe).

Macro (Include) Guard (C++ plus)

• An include guard (macro guard) uses a unique identifier at the pre-processor stage.
• Macro guards prevent double declarations.
• If the identifier is not defined, the code block inside is included; otherwise, skipped.
• All programmer-defined header files must wrap an include guard around function prototypes.
• Example #ifndef MYFUNCTS_H ... #endif.

Parameter Passing

• Review 4.2 Parameter Passing (by value versus by reference).
• Complete multiple-choice questions at the end of 4.2 (Q8 to Q9).
• Stop when reaching 4.3 Arrays as Parameters in Functions.

Pass by Value vs. Pass by Reference

• (Pass by Value)*
• Default argument passing method.
• A copy of the argument is passed.
• Uses 2X memory.
• Safe, as original is not modified.
• Efficient for built-in datatypes (int, float, double, char).
• (Pass by Reference)*
• Uses the address of the argument.
• Uses 1X memory.
• Unsafe, allows modification of original.
• Requires & (e.g., int &a).

Pass by Reference Example

• Demonstrates how pass by reference works in C++.

Function Overloads

• Same function name.
• Same task, different arguments/data types.
• Return type and parameter names aren't factors.
• Standard library functions are often overloaded.

Default Parameters

• Functions can have default values for parameters.
• Defaults are ignored if argument is supplied.
• Default value assignment occurs in the prototype.
• Defaults must be on the right side in the list of parameters.

Recursive Functions

• A function calling itself.
• Can shorten and clarify code.
• Essential for operations with data structures (e.g., graph, tree traversals).
• Disadvantages of recursion: uses more space/time, and can be more difficult to debug.

Example Factorial (Iterative)

• Illustrates an iterative calculation of a factorial.

Example Factorial (Recursive)

• Illustrates a recursive calculation of a factorial.

Three-Tier Architecture Model

• Application architecture using 3 logical/physical tiers:
  • Presentation tier (user interface)
  • Application tier (logic and processing)
  • Data tier (data storage and management).
• Functions should be designed according to the three-tier architecture model.

Earn Your Pre-Work Grade

• Post discussion question & research to D2L.
• Complete Week 11 content module at 100%.

Questions/Clarifications/Help

• Student office hours scheduled with Julie.
• Drop-in times available (on campus).
• Remote via Zoom possible.
• Email: [email protected]
• RRCC campus tutoring available.
• 24/7 online tutoring resources in D2L.