Chapter 2 intro to c++

Question 1

parts of a c++ program messy

Answer 1

//comment
# include  (#preprocessor directive(
using namespace std; (which namespace to use)
int main() ( beginning of function called main)
{      (beginning of block for main)
      cout  << "hello"; (output statement)
      return 0; (send 0 to operating system)
}      (end of block for main)

Question 2

parts of a c++ program

Answer 2

//comment
#beginning of preprocessor directive
< > include file name in #include
( ) used when naming a function
{ } encloses a group of statements
" " encloses a string of characters
; end of a programming statement

Question 3

cout object

Answer 3

display output on computer screen
You use the stream insertion operator &laquo_space;to send output to cout:
cout &laquo_space;“Programming is fun!”;

Question 4

cout object2

Answer 4

Can be used to send more than one item to cout:
	cout << "Hello " << "there!";
Or:
	cout << "Hello ";
	cout << "there!";

Question 5

endl manipulator

cout “hello” «< “world”;

Answer 5

«< “hello \n”

cout &laquo_space;“world”

Question 6

the #include directive

Answer 6

Inserts the contents of another file into the program
This is a preprocessor directive, not part of C++ language
#include lines not seen by compiler
Do not place a semicolon at end of #include line

Question 7

variable

Answer 7

a storage location in memory
Has a name and a type of data it can hold
Must be defined before it can be used

Question 8

literal

Answer 8

a value that is written in to a program’s code
such as a string literal”hello world”
or simply an integer literal like 11

Question 9

identifier

Answer 9

An identifier is a programmer-defined name for some part of a program: variables, functions, etc.
C++ keywords cannot be used as identifiers

Question 10

identifier rules

Answer 10

variable names should be meaningful
first character must be alphabetic character or underscore_
after first character you may use both cases, numbers, or underscores
NO WHITE SPACE
upper and lowers cases are distinct from each other.

Question 11

Integer data types

Answer 11

integers can hold just that, integers: positive and negative whole numbers.
variables of same type may be defined on same( separated by commas, or different lines
different types must be on different lines

Question 12

integer literals

Answer 12

An integer literal is an integer value that is typed into a program’s code
itemsOrdered = 15;
15 is an integer literal

Question 13

integer literals 2

Answer 13

Integer literals are stored in memory as ints by default
To store an integer constant in a long memory location, put ‘L’ at the end of the number: 1234L
Constants that begin with ‘0’ (zero) are base 8: 075
Constants that begin with ‘0x’ are base 16: 0x75A

Question 14

char data type

Answer 14

Used to hold characters or very small integer values
Usually 1 byte of memory
Numeric value of character from the character set is stored in memory

Question 15

char literals

Answer 15

must be enclosed in single quotation marks

‘A’

Question 16

character string

Answer 16

A series of characters in consecutive memory locations:
“Hello”
Stored with the null terminator, \0, at the end

Comprised of the characters between the “ “

Question 17

string class

Answer 17

Special data type supports working with strings
 #include 
Can define string variables in programs:
string firstName, lastName;
Can receive values with assignment operator:
firstName = "George";
lastName = "Washington";
Can be displayed via cout
cout << firstName << " " << lastName;

Question 18

floating point data types

Answer 18

The floating-point data types are:floatdoublelong double
They can hold real numbers such as:
12.45 -3.8
Stored in a form similar to scientific notation
All floating-point numbers are signed

Question 19

types of floating point

Answer 19

single precision: 4 bytes
double: 8 bytes
long double: 8 bytes

Question 20

floating point literal

Answer 20

Can be represented in
Fixed point (decimal) notation:
	31.4159			0.0000625
E notation:
	3.14159E1			6.25e-5
Are double by default
Can be forced to be float (3.14159f) or long double (0.0000625L)

Question 21

bool data type

Answer 21

boolean
represents value of true or false
bool variables are stored as small integers
false is represented by 0, true by 1

Question 22

determining size of data type

Answer 22

The sizeof operator gives the size of any data type or variable:
	double amount;
	cout << "A double is stored in "
  		  << sizeof(double) << "bytes\n";
	cout << "Variable amount is stored in "
  		  << sizeof(amount) 
       << "bytes\n";

Question 23

variable assignment

Answer 23

An assignment statement uses the = operator to store a value in a variable.
boxes = 15
this stores the value of 15 to the boxes variables
variable must be left side

Question 24

variable initialization

Answer 24

To initialize a variable means to assign it a value when it is defined:
int boxes = 15
may initialize some, none or all variables

Question 25

scope of a variable

Answer 25

The scope of a variable: the part of the program in which the variable can be accessed
A variable cannot be used before it is defined

Question 26

arithmetic operations

Answer 26

Used for performing numeric calculations
C++ has unary, binary, and ternary operators:
unary (1 operand)		    -5
binary (2 operands)     13 - 7
ternary (3 operands) exp1 ? exp2 : exp3

Question 27

binary operators

Answer 27

addition +
subtraction -
multiplication *
division /
modulus(remainder) %

Question 28

division

Answer 28

division) operator performs integer division if both operands are integers
If either operand is floating point, the result is floating point

Question 29

modulus

Answer 29

% (modulus) operator computes the remainder resulting from integer division
% requires integers for both operands

Question 30

comments

Answer 30

Used to document parts of the program
Intended for persons reading the source code of the program:
Indicate the purpose of the program
Describe the use of variables
Explain complex sections of code
Are ignored by the compiler

Question 31

single line comment

Answer 31

line begins with //

Question 32

multiple line comment

Answer 32

begins with /*
end with */
same line or spanning multiple lines

Question 33

Named constants

Answer 33

constant variable): variable whose content cannot be changed during program execution
Used for representing constant values with descriptive names:
const double TAX_RATE = 0.0675;
const int NUM_STATES = 50;
Often named in uppercase letters

Question 34

programming style

Answer 34

The visual organization of the source code
Includes the use of spaces, tabs, and blank lines
Does not affect the syntax of the program
Affects the readability of the source code

Question 35

programming style 2

Answer 35

Common elements to improve readability:
Braces { } aligned vertically
Indentation of statements within a set of braces
Blank lines between declaration and other statements
Long statements wrapped over multiple lines with aligned operators

Question 36

prestandard c++

Answer 36

Older-style C++ programs:
Use .h at end of header files:
#include
Use #define preprocessor directive instead of const definitions
Do not use using namespace convention
May not compile with a standard C++ compiler