cpsc quiz 3

iostream

input or output stream

fstream

input and output file stream

ifstream

input file stream

ofstream

output file stream

eof

test for end of input file

cout

standard output

cin

standard input

creating a new file syntax

fstream newfile:

opening a file syntax

newfile.open(“info.txt”, ios::out);

out mode

allows data to be written to a file, ios::out

in mode

allows data to be read from a file, ios::in

close an opened file

newfile.close();

ios::binary

binary mode, data is written to or read from it in pure binary format

read from a file

use either ifstream or fstream class and specify the name of the file

create a file

use either ofstream or fstream and specify name of file

create and open a text file

ofstream Myfile (“filename.txt”)

writing in a file

Myfile « “Writing words”;

iomanip

library used to manipulate output of program, uses showprecision(x), setw(x), showpoiint

showprecision(x)

format to x decimal places

setw(x)

set field/width to x spaces

showpoint

set the format flag for str stream

fail()

true if failbit or hardfail set, false otherwise

bad()

true if badbit set, false otherwise

good()

true if goodbit set, false otherwise

clear()

clear all flags (no arguments), or clear a specific flag

member functions

file stream objects have _________ for special reading and writing, getline, get, put

getline

reads a line of data including whitespace characters, needs name of file stream and name of string

getline syntax

getline(myFile, name);

get

reads a single character from the file

get syntax

gradeFile.get(letterGrade);

put

writes a single character to the file

put syntax

reportFile.put(letterGrade);

outfile.close()

when a program is finished with a file, it must close the file using close like:

binary files

contain data that is not necessarily stored as ASCII text, uses ios::binary flag

abstraction

a recognition of similarities between certain objects, view or representation of an entity that includes only the most significant attributes

order of abstraction languages

machine code, assembler languages, procedural languages, object-oriented programs, modeling languages

procedural abstraction

writing and using subprograms as black boxes, hiding the details of a complex task/process under a method name with parameters

advantages of procedural abstraction

breaking code into pieces, reusing in different situations, easier to test and replace code, hides detail, documentation is easier

data abstraction

collections of data containing data + operations as abstract entities, process of simplifying and representing the whole

advantages of data abstraction

grouping related pieces of information, simplifying the task of reasoning about data, defining and understanding what meaningful operations can be performed on data, easy to modify the code

struct and class

abstraction can be achieved using both ____________ keywords through the concept of abstract classes

struct

user-defined composite data type that groups together variables of different data types under a single name

struct syntax

struct structName {

dataType1 identifier1

dataType2 identifier2

}

member access operator (.)

used to access data into the struct member

member access syntax

structVariableName.memberName

initializing data into a struct member

student newStudent = {“John”, “Brown”, 4.0};

string class

way to represent a sequence of characters as an object of the class, stores the characters a s a sequence of bytes allowing access to a single-byte character

print specific position in string

string_name[position];

print specific string range

string_name.substr(start #, end#);

binary operator +

can be used to perform string concatenation

getline function

to read strings line by line with white space use _______

getline with string syntax

getline(cin, stringName);

relational operators

strings can use ________ to compare

two dimensional array

array (row #, column #)

c-string

specific type of char array that adheres to a convention, fundamentally define by the presence of a null-termination character

c-string header file

#include <cstring>

null characters

if you store a string whose length is less than the array size, the last components are unused and filled with ________

strcpy(s1, s2);

copies string s2 into string s1

strcat(s1, s2);

concatenates string s2 onto the end of string s1

strlen(s1)

returns the length of string s1

strcmp

compares strings character by character

strcmp(s1, s2);

• returns 0 is they are the same

• returns negative if s1<s2

• returns positive if s1>s2

get function

to read a string with blanks, use the _____

get syntax with a string

cin.get(name, 10) → reads 10 characters into name