scis.regis.edu ● CS-361: Control Structures Week 2 Dr. Jesús Borrego Lead Faculty, COS Regis University 1

Topics Homework #1 review Key Terms Chapter 6 (pp ) Activity #1 Chapter 7 (p. 362) Appendix F (pp ) Activity #2 Homework #2 2

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 3

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, indentar 4

scis.regis.edu ● C++ Programming: From Problem Analysis to Program Design, Fifth Edition Chapter 6: User Defined Functions I 5

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 6

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 7

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 8

Sample programs PredefinedFunctions.cpp 9

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 10

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Examples 13

scis.regis.edu ● C++ Programming: From Problem Analysis to Program Design, Fifth Edition Chapter 7: User Defined Functions II 14

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 15

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 16

Void Functions III 17 Function definition syntax: Formal parameter list syntax: Function call syntax Actual parameter list syntax

Void Functions IV 18

Sample programs VoidFunctions.cpp ASCII.cpp CalcGrade.cpp ▫Make sure you check the output of your programs VoidFunc_NoParam.cpp VoidFunc_Param.cpp 19

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 20

Parameter list 21

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 22

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 23

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 24

Sample Program Larger.cpp 25

Activity 2 We (all of us together) will write a program from scratch. Review textbook programming assignment #3 on page

scis.regis.edu ● C++ Programming: From Problem Analysis to Program Design, Fifth Edition Appendix F: Header Files 27

Header files See HeaderFiles.xlsx ▫Headers tab ▫Constants tab 28

Sample programs CharFunctions.cpp Strcat.cpp Strcat1.cpp 29

Activity 3 Work in groups of 2, but groups should be different from last class. Fix program on pages 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 minutes 30

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 31