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CS-361: Control StructuresWeek 2

Dr. Jesús BorregoLead Faculty, COSRegis University

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Topics

•Homework #1 review•Key Terms•Chapter 6 (pp. 320-321)•Activity #1•Chapter 7 (p. 362)•Appendix F (pp. 1247-1253)•Activity #2•Homework #2

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Homework 1 Review

• Program 6, page 173 in the textbook• Use coding standards• Review inputs and outputs• Submit Word documentation• Submit to WorldClass/Desire to Learn before

week 2

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Key Terms

• Compiler – compilador• Hard coded variable – valor usado en vez de

constante• I/O stream – flujo de entradas y salidas• Linker – enlazador• Object code – código objeto• Server – ordenador, servidor, estación de trabajo• Source code – código fuente• Syntax and semantics – sintaxis y semántica• Void type – sin tipo de variable• Whitespace – líneas en blanco, espacio, indentar4

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C++ Programming: From Problem Analysis to Program Design, Fifth Edition

Chapter 6: User Defined Functions I

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Ch. 6: User Defined Functions

•Functions are like building blocks•They allow complicated programs to be

divided into manageable pieces •Some advantages of functions:

▫A programmer can focus on just that part of the program and construct it, debug it, and perfect it

▫Different people can work on different functions simultaneously

▫Can be re-used (even in different programs)▫Enhance program readability

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Predefined Functions

•In algebra, a function is defined as a rule or correspondence between values, called the function’s arguments, and the unique value of the function associated with the arguments ▫If f(x)= 2x + 5, then

f(1)= 7, f(2)= 9, and f(3)= 11

▫1, 2, and 3 are arguments▫7, 9, and 11 are the corresponding values

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Some Math Functions

•Some predefined mathematical functions are: sqrt(x)pow(x, y)floor(x)

•Predefined functions are organized into separate libraries

•I/O functions are in iostream header•Math functions are in cmath header

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Sample programs

•PredefinedFunctions.cpp

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Activity 1

•Type the program on page 323 by hand (Victor)

•Start with your template•Compile and run•Verify your output matches the sample

run shown•Submit the program and output to

WorldClass•Time: 30 minutes

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Examples

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C++ Programming: From Problem Analysis to Program Design, Fifth Edition

Chapter 7: User Defined Functions II

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Void Functions

• Void functions and value-returning functions have similar structures–Both have a heading part and a statement

part• User-defined void functions can be placed

either before or after the function main • If user-defined void functions are placed

after the function main–The function prototype must be placed

before the function main

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Void Functions II

•A void function does not have a return type▫return statement without any value is

typically used to exit the function early•Formal parameters are optional•A call to a void function is a stand-alone

statement

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Void Functions III

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•Function definition syntax:

•Formal parameter list syntax:

•Function call syntax

•Actual parameter list syntax

Void Functions IV

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Sample programs

•VoidFunctions.cpp•ASCII.cpp•CalcGrade.cpp

▫Make sure you check the output of your programs

•VoidFunc_NoParam.cpp•VoidFunc_Param.cpp

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Parameters

•Value parameter: a formal parameter that receives a copy of the content of corresponding actual parameter

•Reference parameter: a formal parameter that receives the location (memory address) of the corresponding actual parameter

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Parameter list

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Value Parameters

•If a formal parameter is a value parameter▫The value of the corresponding actual

parameter is copied into it •The value parameter has its own copy of

the data •During program execution

▫The value parameter manipulates the data stored in its own memory space

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Reference Parameters

• If a formal parameter is a reference parameter– It receives the memory address of the

corresponding actual parameter• A reference parameter stores the address of

the corresponding actual parameter• During program execution to manipulate

data–The address stored in the reference parameter

directs it to the memory space of the corresponding actual parameter

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Reference Parameters II

• Reference parameters can: –Pass one or more values from a function –Change the value of the actual parameter

• Reference parameters are useful in three situations: –Returning more than one value–Changing the actual parameter–When passing the address would save

memory space and time

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Sample Program

•Larger.cpp

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Activity 2

•We (all of us together) will write a program from scratch.

•Review textbook programming assignment #3 on page 172

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C++ Programming: From Problem Analysis to Program Design, Fifth Edition

Appendix F: Header Files

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Header files

•See HeaderFiles.xlsx▫Headers tab▫Constants tab

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Sample programs

•CharFunctions.cpp•Strcat.cpp•Strcat1.cpp

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Activity 3

•Work in groups of 2, but groups should be different from last class.

•Fix program on pages 171-172 so that it returns the correct output.

• Include the header from the coding standards and include the names of the members of the group

•Submit your corrected program to WorldClass

•30 minutes30

Homework 2

•Program 10 on page 174•Follow coding standards•Review input and output

▫Create test cases•Submit to WorldClass/Desire to Learn

before week 3

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