ITP 134 C++ Study Guide
Chapter 2 C++ Fundamentals
Instructions: Use this Study Guide to help you understand the important points of this chapter. See
the book for lots of great programming examples. Important concepts, keywords, statements and
functions are shown in emphasized font.
Code syntax and examples are shown in code font.
Games & Graphics in C++
2nd edition by Tony Gaddis
2.1 The Parts of a C++ Program
CONCEPT: Your first step in learning C++ is to learn to basic parts of a C++ program
Basic structure of a C++ program
#include <iostream>
using namespace std;
// include directive for the library for input/output
// namespace organizes program entries for iostream
int main()
{
return 0;
// Main function. Starting point for the program
// Return 0 means executed correctly.
// Statements end with semicolons ;
}
Comments
// single line comment
/*
block comment
Used for several lines
*/
2.2 Displaying Screen Output
CONCEPT: You write cout statements to display output
in a console window.
Console – old computer term for simple screen and
keyboard. (page 39)
2.3 More about the #include Directive
CONCEPT: The #include directive causes the contents of
another file to be inserted into the program. (page 45)
2.4 A First Look at Variables
CONCEPT: A variable is a named storage location in
memory. (pg 46)
Using the endl Manipulator
Use the endl to start a new line for cout
Using the \n Escape Sequence
Another way to start a new line is to use \n for cout.
See Table 2-1 Common Escape Sequences (page 44) for
other ways to control output.
ITP 134 – Mrs. Eaton
Data Types
See Table 2-3 Some of C++ Data Types on page 48
for more details on data types.
Numeric data types – you must choose the type of
data you will store in a variable. (pg 48)
 int – stores integers (whole numbers) using 4
bytes, range from -2.1B to 2.1B
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
float – stores floating point numbers (real
numbers with a decimal point) using 4 bytes
 double – stores larger integer or real numbers
with 15 digits of precision using 8 bytes
Non-Numeric Data Types
 bool – stores the Boolean values true or false
using 1 byte
 char – stores a single character using 1 byte
 string – stores strings of text so size varies
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You can optionally initialize and declare a variable in a
single statement.
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Part 1 of book: Use int for integers and double for
real numbers. (pg 49)
Part 2 of book: Use int for integers and float for real
numbers. The App Game Kit uses float instead of
double. (pg 54)
You can name variables whatever you want as long as
you follow these rules: (pg 47)
 Must begin with a letter a-z, A-Z, or an _
(underscore)
 Must contain only letters a-z, A-Z, or _. Cannot
contain special characters like $, &, % etc.
 Cannot contain spaces.
 Are case sensitive. You must use uppercase,
lowercase exactly each time you use the
variable.
 Cannot use C++ reserved words. See Table 1-2
on page 16 for C++ reserved word list.
Naming conventions (pg 48)
 Use camelCase with a lowercase starting letter,
and then uppercase for each word. Such as
centerPointX. We will be using camelCase in
this book and in this class like many
professionals.
 Not recommended to run words together using
all lowercase. Really hard to read names such
as centerpointx.
 For constant names use a _ (underscore) to
represent a space. Such as MAX_VALUE
Declaring Variables
datatype variableName1,
variableName2, variableName3;
Variable declaration (pg 80) where datatype is
int, float, or double. Declare more than one
variable and separate with commas.
Variable Initialization
variableName = value;
ITP 134 – Mrs. Eaton
datatype variableName = value;
Initialize a variable (pg 51) declare and assign in
one statement.
int speed = 60;
double amount = 23.90;
Declaring Multiple Variables with One Statement
Variable Names

Assignment statement (pg 51) Assign a value
to a variable. Variable is always on the left and
the assigned value always on the right. This is
different from math class.
int month, day, year; or
int month=5, day = 4, year =
1865;
Where to Declare Variables

Local variable – declare a variable inside the
main function. We’ll see more places to declare
local variables later.
Declare Variables Before Using Them

An uninitialized variable is a variable that has
been declared, but has not been assigned a
value yet. You want to assign a value to a
variable before you exactly use it, otherwise
you will have unpredictable results.
Numeric Literals
CONCEPT: A numeric literal is an item of data that is
typed into a program’s code. (actual number or string
instead of using a variable). (pg 81)
 A numeric literal is a number typed directly into
code. (pg 52)
 A string literal is a string typed directly into
code surrounded by double quotes.
Variables and Assignment Compatibility
Warning: If you try to assign a real number to an integer
data type, the numbers after the decimal point will be
truncated. This may not be what you were expecting.
(pg 52-53)
Chapter 2 Study Guide – 2nd Edition
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2.5 Reading Keyboard Input
CONCEPT: You write cin statements to read input from
the keyboard. (page 55)
// declare age variable
int age;
// prompt user
cout << “What is your age? “;
// read value from keyboard
cin >> age
2.6 Comments, Blank Lines and
Indentation
CONCEPT: Comments are brief notes that are placed in
a program’s source code, explaining how parts of a
program work. Programmers commonly use blank lines
and indentation in program code to give the code visual
organization and make it easier to read. (pg 58)
// Use for single line comments
Banner Comments for Program Submissions Example
/*************************************
***
Programmer: Carlotta Eaton
Program: Program 2-11 SalePrice.cpp
Purpose: Program calculates sales
price
**************************************
**/
2.7 Performing Calculations and Working
with Numbers
CONCEPT: To perform calculations in a C++ program,
you use math operators to create math expressions. (pg
60)
 +
(add)
 –
(subtract)
 *
(multiply)
 /
(divide) and
 %
(modulus gives remainder of division)
 You will usually need to rewrite math
equations using C++ operators.
The Order of Operations
Operation precedence – same as math classes (pg
62-63)
1. First perform operations inside ( )
2. Perform * / and % in order from left to right
ITP 134 – Mrs. Eaton
3. Perform + - in order from left to right
Grouping with Parentheses
Group expressions with () to change the order of
operations above (pg 63)
Integer Division
In C++, when you divide an integer by an integer the
result is a integer (truncates the fractional portion of
the result). This may not be what you were expecting
so be careful. (pg 63-64)
Combined Assignment Operators
C++ is one of the languages where you have shortcuts
for some common assignment operations. (pg 66)
“short cut operator”
+=
-=
*=
/=
%=
Example
x += 5;
y -= 2;
z *= 10;
a /= b;
c %= 3;
Means
x = x + 5;
y = y – 2;
z = z * 10;
a = a / b;
c = c % 3;
Mixed-Type Expressions and Data Type
Conversion
C++ follows these rules when evaluating expressions
with both int and double values: (pg 66-67)
 When operation on 2 int values, the result will
be int (Integer).
 When operation on 2 double values, the result
will be double (real).
 When operation on int and double, the int will
be converted to a double and then result will be
double.
You can also explicitly change the data type of a
variable: (pg 67-68)
intValue = static_cast<int>(doubleValue)
2.8 Named Constants
CONCEPT: A named constant is a name that represents
a value that cannot change during the program’s
execution.
Use the const keyword to declare a constant. (page 71)
const datatype CONSTANTNAME =
value; // general use
nd
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const double INTEREST_RATE = 0.129;
//example
 Use all caps for constant names is a good
programming practice. (pg 72)
 You must declare and initialize a constant in the
same statement, otherwise you will get an
error.
2.9 Math Functions in the Standard
Library
CONCEPT: The C++ standard library provides several
functions for performing advanced mathematical
operations. Include the <cmath> library to use these
functions.
pow(Base, Exponent)
// returns base exponent (pg 74)
sqrt(value)
//returns the square root (float) of a value (pg 75)
floor(value) // returns the smallest whole
number less than or equal to a value (pg 75)
Trigonometry Functions (pg 75)
cos(angle)
in radians (pg 75)
sin(angle)
tan(angle)
//returns cosine (float) of angle
//returns sine
//returns tangent
2.11 The char Data Type
CONCEPT: You use the char data type to store a single
character in memory. (pg 79)
Here is the syntax to declare and initialize a char
variable.
char letter;
// declaration
letter = ‘A’;
// use single
quotes
You cannot assign strings to char variables.
Chapter 2 Program Examples
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2.10 Working with Strings
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CONCEPT: You use the standard library’s string class to
create objects that can hold strings. (pg 76)

#include <string>
//
include string library to use
strings
string movie;
//
declaration
movie = “Wheels of Fury”; //
use double quotes for strings
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Program 2-1 HelloWorld.cpp (page 40)
Program 2-2 MultipleItems.cpp (page 41)
Program 2-3 OneLine.cpp (page 42)
Program 2-4 ThreeLines.cpp (page 42)
Program 2-5 EscapeSquence.cpp (page 43)
Program 2-6 VariableDemo.cpp (page 50)
Program 2-7 VariableInit.cpp (page 51)
Program 2-8 OneValue.cpp (page 53)
Program 2-9 InputExample.cpp (page 56)
Program 2-10 SimplePayroll.cpp (page 56)
Program 2-11 SingleLineComment.cpp (page
58)
Program 2-12 MultiLineComment.cpp (page 59)
Program 2-11 SalePrice.cpp (Page 61-62)
Program 2-12 SecondsConverter.cpp (page 6465)
Program 2-13 TypeCast.cpp (page 67-68)
In The SpotLight: Calculating Percentages and
Discounts (page 68-69)
In The SpotLight: Calculating an Average (page
69-71)
Program 2-16 NamedConstant.cpp (page 73)
Program 2-17 PowFunction.cpp (page 74-75)
Program 2-18 StringExample.cpp (page 76)
Program 2-19 StringInput1.cpp (page 77)
Program 2-20 StringInput2.cpp (page 77-78)
Program 2-21 CharLiterals.cpp (page 79)
There is a limitation to using cin to read string input. A
cin statement can read only one word. (pg 77)
ITP 134 – Mrs. Eaton
Chapter 2 Study Guide – 2nd Edition
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