Files, File Reading, File Writing

Question 1

where do computers store files

Answer 1

secondary devices eg hard disk, flash drives, DVDs etc

Question 2

what is a byte-based stream

Answer 2

when input and output is in binary format

Question 3

how many bytes in a characer

Answer 3

2

Question 4

how many bytes in an int

Answer 4

4

Question 5

how many bytes in a double

Answer 5

8

Question 6

what is character based stream

Answer 6

output and input is a sequence of characters

Question 7

example of character based stream

Answer 7

ASCII

Unicode

Question 8

when would binary storage be used

Answer 8

images, videos

Question 9

example of byte based file extensions

Answer 9

.jpeg

.png

Question 10

example of character based file extensions

Answer 10

.txt

Question 11

3 java input/output streams directly attached to console

Answer 11

system. in
system. out
system. err

Question 12

can system.err be redirected? why might you want this?

Answer 12

yes

eg send to manufactures so they can debug and fix the problem

Question 13

void write (byte[] arr) method in javaFileOutput stream does what

Answer 13

writes arr.length bytes from the bytes array to the output stream

Question 14

how to write specific amounts from byte array

Answer 14

void write(byte[] array, int offset, int length)

Question 15

how to write an individual byte in the array

Answer 15

voif write(int b)

Question 16

how to close the file

why

Answer 16

name.close();

nothing will we written until its closed

Question 17

convert the string myString to a byte array

Answer 17

byte [ ] byteArray = myString.getBytes( );

Question 18

what does the function getBytes( ) allow us to do

Answer 18

get the string as a sequence of bytes

Question 19

getBytes is a fucntion within what class

Answer 19

fileOutput stream

Question 20

what is java file input stream used for

Answer 20

read from a file

Question 21

what does int read() method in the file input stream do

Answer 21

returns the number of bytes that were read from the input file

Question 22

how to read up to b.length bytes of data from file input stream

Answer 22

iint read(byte [ ] b);

Question 23

how to read a certain length of bytes from a file input stream

Answer 23

int read( byte [] b, int offset, int length)

Question 24

how to know when file has finished being read

Answer 24

will return -1

Question 25

what does buffered reader and writer allow

Answer 25

computer to continue to operate rather than hanging while waiting to read/write

Question 26

what must be passed into a buffered reader or writer

Answer 26

the file reader or writer

Question 27

what does the flush fucntion do in the buffered classes

Answer 27

forced out before we close the file

Question 28

instead of using file output class and converting the bytes to string ourselves, what can be used

Answer 28

file writer

Question 29

how to get name of file

Answer 29

file.getName();

Question 30

how to get absolute path of file

Answer 30

file,getAbsolutePath();

Question 31

how to get length of file

Answer 31

int file.length();

Question 32

how to make a new file

Answer 32

file file = new file (“”);